This film is influenced by Once Upon a Time in America (1984) and the real-life accounts of India's most notorious gangsters, Haji Mastan and Dawood Ibrahim.
Emraan Hashmi's character Shoaib Khan is loosely based on the underworld leader, Dawood Ibrahim. Dawood Ibrahim was on Forbes 2008 list of The World's 10 Most Wanted criminals. Ajay Devgan who plays Sultan Mirza and Randeep Hooda who plays ACP Agnel Wilson also played characters based on Dawood Ibrahim in Company (2002) and 'D' (2005).
This film is based on the true-life tales of Haji Mastan and Dawood Ibrahim, the top racketeers of Bombay and the very first to be considered celebrities. Mastan ruled the Bombay gangland from the 1960s-70s, before being succeeded by Ibrahim in the 1970s-80s.
Ekta Kapoor gifted Ajay Devgan a luxury 1967 vintage car which he drives in the film as he loved the car very much.