Development While working on
Mahaan in mid 2021, director
Karthik Subbaraj had narrated a script to
Suriya which impressed the actor. However, since the script required extensive pre-production and filming time, they decided to proceed with another script that also impressed him. Although they had finalised to collaborate back then, both of their respective prior commitments delayed the collaboration. Two-and-a-half years later, on 28 March 2024, Subbaraj announced through his social media accounts that he would join hands with Suriya for his next directorial venture after
Jigarthanda DoubleX (2023). The project would be jointly funded by Subbaraj's
Stone Bench Creations and Suriya's
2D Entertainment banner. Suriya and
Jyothika would be credited as producers, while Stone Bench's main producer Kaarthikeyan Santhanam would be credited as co-producer along with Rajsekar Pandian, the head of 2D Entertainment. The project was kept confidential by the makers until its announcement. The film was made on a budget of crore. production was set to begin after the actor completed his film with
Sudha Kongara which was then known as
Suriya 43. However, a few days later, it was reported that, since the start of Kongara's film would take a few more months, they were planning to complete the shooting of the project in the meantime. The film was touted to be as a
gangster action drama film. But Subbaraj later clarified that the film, set in 1990s, is a
romance film which also involves major
action sequences.
Pre-production Subbaraj had met Suriya prior to the shooting of
Jigarthanda DoubleX and narrated a one-liner, which the latter requested to develop. It took him several months for the writing and pre-production. Charukesh Sekar and Sritharan Someetharan collaborated with Subbaraj on the script discussion. After the release of
Jigarthanda DoubleX, Subbaraj narrated the entire script to the actor. The dialogues for the
Telugu and
Hindi-dubbed versions were written by Hanumaan Choudary and Mohan Nair. A
casting call was announced by the makers in late April 2024. On the occasion of his birthday (15 May),
Santhosh Narayanan was announced as the film's composer by the production house, in his eighth collaboration with the director. Two weeks later, the team announced that Shreyaas Krishna would handle the cinematography, in his third collaboration with Subbaraj after
Jagame Thandhiram (2021) and
Mahaan (2022). In addition to Shreyaas Krishna, the technical crew of art directors
Jacki and Mayapandi, editor Shafique Mohamed Ali, stunt choreographer Kecha Khamphakdee and costume designer Praveen Raja were announced the same day. In May 2024, the team shot the promotional video for the film for nearly three days. Prior to the commencement of the first schedule, the team had constructed a set at
Port Blair located in
Andaman and Nicobar Islands, for filming an action sequence.
Casting Suriya would sport two different looks in the film. One with a
Fu Manchu moustache and
mullet hair, and another with a trimmed beard, mustache, and a shorter hairdo. In mid-May,
Pooja Hegde was reported to play the female lead opposite Suriya, marking her first film with both Suriya and Subbaraj. Her inclusion was confirmed on 1 June by the production house. The film would be her third Tamil film after
Mugamoodi (2012) and
Beast (2022). Hegde reportedly received a remuneration between and . Subbaraj revealed to
Ananda Vikatan that he cast her after being impressed with her performance in
Radhe Shyam (2022). Following a look test, she began learning
Tamil for her role. Aavni, daughter of actress
Anjali Nair, plays the younger version of Hegde's character. After initially being reported as part of the cast,
Jayaram and
Nassar were confirmed during the film's preliminary shooting, with both playing important roles. The former's son,
Kalidas Jayaram, was also reported to be part of the cast after being spotted during the shooting, thus reportedly marking his second on-screen collaboration with his father, following
Ente Veedu Appuvinteyum (2003), after 12 years. However, Rajsekar Pandian denied Kalidas Jayaram's inclusion in the film, stating, "Kalidas came on the last day shoot of Jayaram sir when the team cut a cake that has been misinterpreted."
Prakash Raj would also play a role in the film, marking his fourth collaboration with Suriya after
Nerukku Ner (1997),
Singam (2010) and
Jai Bhim (2021). Vidhu, who portrayed the role of Shettani in Subbaraj's
DoubleX, would play the role of an antagonist in
Retro.
Singampuli,
Sujith Shankar, Thamizh,
Ramachandran Durairaj,
Prem Kumar, Sandeep Raj and
Remya Suresh were cast in prominent roles. While Karunakaran and George would make their respective fourth and second collaboration with Subbaraj after
Pizza (2012),
Jigarthanda (2014),
Iraivi (2016) and
Jagame Thandiram respectively, Singampuli would make his fourth collaboration with Suriya after
Pithamagan (2003),
Perazhagan (2004) and
Maayavi (2005). Although Kannada actor
Dhananjaya was approached for a prominent role, he could not sign it due to scheduling conflicts.
Shriya Saran joined the production in August 2024, and shot for the
item number "Love Detox".
Filming , where parts of the film were shot.|right
Principal photography began with the first schedule on 2 June 2024 at Port Blair in Andaman and Nicobar Islands. Suriya, Hegde and Jayaram arrived at the location the previous day. Firstly, the team shot action sequences, choreographed by Kecha Khamphakdee, at a specially erected set. A song shoot featuring Suriya and Hegde was also held in early June 2024.
Sujith Shankar joined the first schedule on 22 June 2024, while filming happening at
Cellular Jail. A dance number featuring Suriya and Hegde, choreographed by
Sherif Master was completed in late-June 2024. On 28 June, Joju George shared a video of himself on a boat in Andaman Island, revealing he joined the sets. The first schedule ended on 4 July 2024 at Andaman. The second schedule began on 26 July at
Ooty. This schedule was reportedly held for 1520 days, where the team had shot few scenes at the scenic backdrop in
Nilgiris. A dance number featuring the lead cast with numerous dancers was shot in late-July 2024 at Ooty. Later it was reported that after ending the Ooty schedule, the team moved to
Kanyakumari on 31 July, which turned to be false. On 7 August, Suriya sustained a head injury on the sets, while filming an action sequence at Nawanagar Palace, Ooty. Although, Rajsekar Pandian tweeted that it was a minor injury, Suriya took a break from filming for a few days for recovery, which resulted in the filming being halted. On 14 August, Suriya returned to the sets to resume shooting, with several
Russians and
Afghans participating. Shooting reportedly happened at three hotels in the particular schedule. A song featuring Shriya Saran was shot in this schedule. This schedule was completed on 17 August 2024, with 70% of the film's shooting has been completed with this schedule. By mid-August, Jayaram completed filming for his portions. A day later, on 19 August 2024, the next schedule was intended to begin at
Idukki in
Kerala for the two-day shoot; but was delayed. The schedule began with filming in
Kaliyar area,
Thodupuzha, at Idukki on 8 September 2024. The Kerala schedule, which went on for two days, ended on 9 September with a night shoot. The team erected a jail set in
BSNL office in Chennai in mid-September for the
Chennai schedule, which included a song ("Kannadi Poove") being intended to be shot. Rehearsals for the song, choreographed by Sherif was done in later days. The final schedule began in late-September in Chennai, with Suriya trimming his beard and moustache for this schedule. Hegde had completed shooting for her portions by 24 September. This schedule, which took place for two weeks, was completed by 6 October 2024, resulting in the film's principal photography being
wrapped. A 15-minutes
long single shot sequence involving action, song ("
Kanimaa") and drama scenes were also shot while filming. The sequence in the title teaser featuring Suriya and Hegde was shot at night in
Varanasi, where 100-200 clay oil lamps were used to create a twilight effect. 80% of the film was reportedly shot on sets.
Post-production After filming was completed, the film entered into an extensive
post-production phase. Subbaraj revealed that he will spend more time for the film's post-production, resulting in the film's release plans for
Pongal (14 January 2025) being deferred. Shafique Mohamed Ali renewed his association with Subbaraj after
Jigarthanda Double X and handled the editing for the film. The film's
visual effects were done by Lorven Studios and was
supervised by S. Hariharasuthan. Suresh Ravi handled the
colour grading,
digital intermediate and
previsualisation. S. Alagiakoothan worked on
sound design and Suren G. handled the
sound recording,
editing and
mixing of the film. Santhosh worked on the film's background score in November 2024. Joju George completed his dubbing by January 2025, while Hegde had completed her dubbing the following month. She dubbed for her own voice, the first time for a Tamil film. The final phase of post-production began by March 2025. Suriya completed dubbing for his portions in early-April 2025. The film's final edit was ready by mid-April 2025 and was submitted to the
Central Board of Film Certification (CBFC) that month. == Music ==