The film is based on the history of Haji Mastan(played by Ajay Devgn) the first celebrity "Don" of India who later reformed, and is about the early gangster and smuggling phase in Mumbai, in the 60s and 70s and revolves around the birth of Mumbai Mafia in the 70s and 80s. Mastan was responsible for introducing Dawood to world of crime and gradually passed him the power, retiring himself. Mastan's rule and authority is also challenged by Shoaib (played by Emraan Hashmi) who is a budding gangster.
Parallel to the main plot will be the story of Mastan's unrequited love during the 60s for Indian actress Madhubala (played by Kangna Ranaut).
This movie, produced by Balaji is set to encompass the full range of leading figures in the Mumbai underworld at that time including possibly Dawood Ibrahim, Abu Salem, Chhota Rajan, Chhota Shakeel and Arun Gawli – whilst at the same time exploring the social and economic factors that create such people and drives them to follow the routes in life that they do.