Mumbai, May 5 (IANS): The trailer of Ribhu Dasgupta's film, "Te3n", which stars megastar Amitabh Bachchan, Vidya Balan and Nawazuddin Siddiqui, was launched here on Thursday.

"We want the audience to promote the film. It's a unique idea by inviting people through social networking sites and asking them to let us know how we can promote the film," Amitabh said about the promotional strategy of the film at the trailer launch event here. 

The trailer talks about the missing granddaughter of Amitabh's character in the film.

"Ribhu wanted me to play a weak character, who is distressed by the fact that there would be a tragedy in his family and how he's going to go about it," he said.

The first poster of "TE3N", which shows Amitabh and Nawazuddin on a scooter, was released a few days back. Vidya plays a police officer in the film. 

The film is entirely based in Kolkata and numerous photographs during its shoot have already been out due to the shoot at real locations.

"One thing about this film is that there was no set made anywhere. All the locations that you can see are all actual locations and there's a different charm about them. I used to wonder how we would shoot in certain places, such as the most difficult chowraha near Grand Hotel, where there is immense crowd," Big B said. 

Produced by "Kahaani" director Sujoy Ghosh, "TE3N" is set to release on June 10.