Critics noted the freshness of Bose's narration style which involves breaking the fourth wall, a device not commonly used in Indian cinema.
In 2006, Bose starred in the first of a trio of Bengali films, Aniruddha Roy Chowdhury's Anuranan.
He also played the antagonist in the 2013 Tamil-Hindi film Vishwaroopam. He is also notable for his social activism: he participated in the relief efforts that followed the 2004 Boxing Day tsunami and is also the founder of the anti-discrimination NGO, The Foundation.
Kaalpurush, Bose's second Bengali film, was released commercially in April 2008.
Kaalpurush details a father-son relationship and earned writer-director Buddhadev Dasgupta a National Film Award for Best Feature Film.
Bose's second film pairing with Konkona Sen Sharma, 15 Park Avenue released in January 2006.
Directed by Aparna Sen and filmed in English, 15 Park Avenue won the 2006 National Film Award for Best Feature Film in English.
Anuranan was well received on the festival circuit and ran successfully for three months in Bengal.
It was then dubbed into Hindi and released nationally.
In 2002, Bose starred opposite Konkona Sen Sharma in Aparna Sen's art film Mr. In 2003, Bose entered mainstream Bollywood cinema with Jhankaar Beats in which he played one of two friends, R. Burman fans who are obsessed with winning a music competition.
Boosted by a successful soundtrack, Jhankaar Beats was a surprise hit in urban multiplexes The same year, Bose appeared in another Bollywood film, Mumbai Matinee which saw a UK release.
Bose continued working in a mix of mainstream and arthouse films in 2008, with the English-language film, Before the Rains.
Before the Rains was released in the US and the UK and Bose's performance was praised by many critics, although the film received mixed reviews.
After his mother's death in 1987, Bose began working as a copy writer at Rediffusion and was later promoted to advertising creative director.