"If we don't give a thought before signing a film, there is no point. We have to do numbered films - you might do 100 or 200, but they should be such that people say, 'He has done 50 films, but all are fantastic'," the 28-year-old said here Friday at the Lavasa Women's Drive Awards Ceremony.
"Also, if we don't think before signing a film, we will soon be out of the industry because we do not have any other kind of support here," he added.
Raj Kumar has earlier featured in films like "Love, Sex Aur Dhokha", "Ragini MMS" and "Shaitan".
He admits "there should be a good story, good character which challenges me as an actor".
"I should get something to explore in a character," he said about his choice of roles.
Raj Kumar will next be seen in "Shahid",w hich had itss world premiere at the 2012 Toronto International Film Festival's 'City to City' programme.
The film is slated to release in India this year. The actor says it's a very inspirational film.
"'Shahid' is a biopic. Its about this lawyer Shahid Azmi who was shot dead in Mumbai in 2010. It is his story. It's an inspirational film, hard-hitting but factual," he said.