During his career at the KPAC, Mohankumar met actress Sobha Mohan, who is the daughter of the late actor Kottarakara Sreedharan Nair and she acted in almost all his plays. Later, he got married to her and was staying at an apartment at Tripunithura. He was preparing to shift to his newly bought flat in Kochi.
Mohankumar started acting in plays at the time of his higher studies in Fathima Matha College in Kollam. He was very handsome with powerful elegant voice and he could attract the youth. So he could win the post of Arts club secretary in the college union election without the support of any political parties.
The Malayali worked with leading troupes like Changanasserry Githa, KPAC, Poonjar Navadhara, Venjaramoodu Souparnika and Kalidasa Kalakendram of O Madhavan. His first professional drama was Saapasila, which was performed in 1979. Later, started his own troupe 'Janani Kalamandir' in 1985. This troupe presented several dramas.
Mohankumar entered film world and acted in films like Malsaram, Venal, Chillu, Radha Ennna Penkutty, Ragam Thaanam Pallavi, Chakravaakam, Thanmathra, Chattambinad and Nivedyam. He played the lead role in the film Matsaram. In Nivedyam, he acted with his son Vinu Mohan, who was the hero in the film. He also acted in several documentaries. His plays are Ramapurathu Warrier, Mudra and Chakravarthi.