The actor can currently be seen in Paan Tomar Singh playing a running champion-turned-outlaw.
He told The Times of India: "[The fluffy stuff] never came to me naturally. This mainstream vs niche thing, you can see it as a conflict, but I am trying to bridge it. I am also trying to do entertaining stories. I want to entertain people, but with some substance.
"The director creates the story, he fits you there. There are so many actors who can do wonders if put into the right hands. Correct casting is critical.
"But it's not their - the director's - need. It's my need. If I'm doing a film in two months, and it is giving me a lot of money - and then there's a film where I am getting one-fourth of the money, and it takes five months of my time, but it's a role like The Namesake, I'll take that. That's a choice I have to make.
"But why that work came to me in the first place - whether The Namesake or others - I cannot decipher that. I am incapable and too limited to be able to really understand that."
In February, Khan said he had loved playing Singh because the real-life figure reminded him of his own father.
The Slumdog Millionaire star replaced Neil Nitin Mukesh in the crime thriller Saheb Biwi Aur Gangster in January.