Kunal was introduced in Kathir’s 1999 romantic film Kadhalar Dhinam, alongside Hindi actress Sonali Bendre. He played a young student who falls in love with Bendre’s character over the Internet.

After the success of Kadhalar Dhinam, Kunal appeared in a series of good movies like Paarvai Ondre Podhume (2001) and Punnagai Desam (2002). Then, he appeared in many flops like Pesadha Kannum Pesume, Enge Enadhu Kavithai and Unarchigal. Several of his other films had delayed releases or were shelved, like Rithik’s Kadhalithal Anandam, which would have featured him alongside Livingston and Kausalya. When he was unable to find roles as an actor, he served as assistant editor for several films and turned to producing. His last film was Nanbanin Kadhali, which released in 2007.

On 7 February 2008, Kunal was found hanging from the ceiling in his Mumbai apartment by actress Lavina Bhatia. The apparent suicide was challenged by his father Rajendra Singh who claimed that the body showed signs of suspicious bruising. Bhatia was detained by police in connection with his death, but she was later released after the police could not prove a motive. The police were unable to prove that anyone was present in Kunal’s apartment at the time of his death and ruled out Bhatia as a suspect as Kunal had a black belt in karate; furthermore, Kunal had attempted suicide by slashing his wrists several months earlier. At the time of his death, Kunal was working on a Hindi film, Yogi, which was being produced by his newly formed production company Balagiri. The case was referred to CBI and Prof T D Dogra of All India Institute of Medical Sciences. He examined the scene of crime along with CBI and opined in favor of suicide.