'Ra.One' that is gearing up for a Diwali release in less than three weeks has gotten Amitabh Bachchan to do a voice over for an important sequence in the film.

Having done a cameo with Superstar Rajinikanth, a legend in the film industry, Khan has now brought the other legend, Amitabh Bachchan also to the 'Ra.One' family. This has upped the film's oomph quotient among movie goers.

Big B is known for his voice as much as the actor in him is popular and the dubbing will take place today. Looks like SRK is leaving no stones unturned, what with cameos by Rajini, Priyanka Chopra and Sanjay Dutt and now a voice over by Big B.

"Getting Superstar to do a cameo itself increased much hype for the film in south as the actor is recovering from his illness, this is first appearance on big screen after his illness and so fans are eagerly awaiting the film for that one scene itself this Diwali", reveal trade sources. "And now convincing Amitabh Bachchan for lending his voice has further increased the buzz", they further add.

And throughout the marketing guru is tight-lipped about his villain Arjun Rampal and his look in the film which is going to be a major surprise packet.