The project is tentatively titled "Dragon" and it will be Ayan and Ranbir's third film together after "Wake Up Sid" and "Yeh Jawaani Hai Deewani".
"People are talking about this film from very long time. I have completed the script of this film. Finally, Karan Johar (the film's producer) has approved the script.
"So, hopefully in early 2016, I'll be able to talk more about the movie", Mukerji said here on the sidelines of a premiere of "Star Wars: The Force Awakens" on Wednesday night.
Some of Ranbir's films have not worked wonders at the box office in recent times. But Mukerji, who's a good friend of teh actor, is not worried about it.
"I know his films are not working right now. But it's okay. This is part and parcel of the game," he said.
Ranbir was last seen on the big screen in Imtiaz Ali's "Tamasha".
