The casting director of the film, Shahid Husain, apparently had first approached Neil Nitin Mukesh and Kunal Kapoor for the role, but for some reason that didn't work out and so Shiney got the big break.
The makers were a little sceptical about casting the actor who is still fighting a case for alleged sexual abuse of his maid, but given the talent the man possesses, they decided to go ahead with him. Wishing Shiney all the best.