Ramasimhan made his directorial debut with the 1988 Malayalam film
Mamalakalkkappurathu, for which he won the
Kerala State Film Award for Best Debut Director that year. In 1995, he directed
Pai Brothers, a comedy-drama starring
Innocent and
Jagathy Sreekumar as two entrepreneurs entrapped in a
love triangle. His 1997 comedy film
Junior Mandrake is one of his best known works, starring
Jagadish and Jagathy Sreekumar. It was based on the
bust of Junior Mandake which is believed to be a
jinx. The film was a commercial success. In 2002, he directed another comedy film,
Bamboo Boys, about four tribal men who come out of jungle on a quest to find a doctor in the city. His 1996 drama film
Rabia Chalikkunnu won the
National Film Award for Best Educational/Motivational/Instructional Film at the 44th
National Film Awards. It was followed by
comedy-drama films
Gramapanchayath (1998),
Kudumba Vaarthakal (1998) and
Swastham Grihabharanam (1999). His directorial
Senior Mandrake (2010), a sequel to
Junior Mandrake, received unfavourable reviews. In 2011, he was banned by FEFKA for associating with acot
Thilakan and directing the film
Achan with him in the lead role. In 2012, he directed
Ideal Couple. In 2020, Ramasimhan announced a film on
Variyankunnath Kunjahammad Haji, which was produced through
crowdfunding, titled
1921: Puzha Muthal Puzha Vare, based on the 1921
Malabar rebellion. The film was released in March 2023. ==Personal life==