Fardeen Khan was the first choice for Neil Nitin Mukesh' s role.
The research Director Madhur Bhandarkar was doing for the movie was interrupted by The 26/11 Mumbai attacks as the film is based on Indian Jails and he wanted Neil Nitin Mukesh to visit Tihar Jail, Delhi. But Neil was refused due to security reasons and increased security in Tihar Jail after the attack.
Sunil Shetty was the first choice for Manoj Bajpayee's role.
The character of Joe Dsouza played by Mirza Ali Quli was based on the 2006 hit and run case of Alistar Pereira,where he drove his car on construction workers sleeping on pavements of Bandra Carter Rd.
After declining supporting roles for years,Manoj Bajpayee finally agreed to play one in Jail. After Satya,Manoj only wanted lead or parallel lead roles in films. He even declined Jackie's role in Devdas. He finally agreed to do jail due to his friendship with Madhur Bhandakar.