Early career Gill was born in Sarabha, a village located in the
Ludhiana district of
Punjab. Despite his father and uncle being more fond of
hockey, Gill found a passion for
football and would usually play with his friends at a nearby ground. The camp lasted for three days and at the end, Gill, alongside India teammate
Bidyananda Singh, was selected to participate in the All-Star Game. During the game and the camp overall, both Gill and Singh managed to catch the eye of European clubs such as
Barcelona and
Inter Milan. Two years later, in 2015, Gill helped the
AIFF Elite Academy win the
2014–15 I-League U19.
Bengaluru FC After spending four years with the
AIFF Elite Academy, Gill signed his first professional contract with
Bengaluru FC of the
I-League on 23 August 2016. Head coach
Albert Roca was very pleased with the signing of Gill, stating "The club’s philosophy is to give young talent a stage and I believe that’s exactly what Gursimrat has got. He is talented, works hard and wants to keep improving which is a good sign for anyone taking the professional path." He eventually made his professional debut for the club the next season on 18 April 2017 in the AFC Cup against
Abahani. Gill came off the bench for
Nishu Kumar in the 89th minute as Bengaluru FC won 2–0. Gill then made his league debut for Bengaluru FC during the final game of the season against
Churchill Brothers on 29 April 2017. He played 74 minutes as Bengaluru FC won 3–0.
NorthEast United On 21 July 2017, after not being retained by
Bengaluru FC, Gill was drafted in the 10th round of the
2017–18 ISL Players Draft by
NorthEast United of the
Indian Super League.
Bengaluru FC On 11 June 2018,
Bengaluru FC announced they had signed Gill on a two-year deal.
Bengaluru United On 17 September 2020, Gill joined
I-League 2nd Division club
FC Bengaluru United for the
2019–20 I-League Qualifiers.
Sudeva Delhi On 16 October 2020, Gill joined I-League side
Sudeva Delhi FC on a two-year deal. He made his debut for Sudeva on 9 January 2021 against
Mohammedan SC.{{Cite web|date=9 January 2021|title=Sudeva vs. Mohammedan SC|url=https://www.espn.in/football/match?gameId=590506 ==International==