While Ranbir Kapoor has started prepping for the biopic on Sanjay Dutt, rumours are trickling in about the rest of the cast. If buzz is to be believed then Akshaye Khanna has been roped in to play the late Sunil Dutt, depicting the intimate relationship of father and son. On the other hand, Tabu has been approached to portray the late actress Nargis on the silver screen. Celebs & Cinema had earlier reported that Sonam Kapoor too is a part of this biopic, as she will be playing Dutt’s love interest on screen. The makers, including Rajkumar Hirani, are tight lipped about the cast, with no official announcements being made even for Tabu and Akshaye Khanna. Director Rajkumar Hirani will begin shooting with Ranbir Kapoor in January for this much-written-about biopic.