D. N. Tripathi, a lyricist, attempts to write a biography on Sanjay “Sanju” Dutt, comparing him with Mahatma Gandhi. A flabbergasted Sanjay has him thrown out. The Bombay High Court delivers its verdict regarding the 1993 Bombay bombings and sentences Dutt to five years jail term for violating the Arms Act. Manyata Dutt approaches Winnie Diaz, a London-based writer, to write Sanjay’s biography and present his version of his life to the public. Although unwilling at first, Winnie is asked by Zubin Mistry, a real estate builder to not write the biography, which intrigues her. Winnie first interviews Sanjay, and his life is revealed in a flashback.
Sanjay’s father Sunil Dutt plans to launch his acting career in Bollywood with the film Rocky (1981). Upset over his father’s controlling behaviour on set, Sanjay is encouraged by his friend Zubin “God” Mistry to try drugs for the first time. Sanjay soon discovers that his mother Nargis is suffering from cancer and is taken to New York for treatment. This incident furthers his descent into alcoholism and drug addiction. He meets Kamlesh, a fan of Nargis, in New York, and they become quick friends. Kamlesh manages to make Sanjay stay his addiction; after learning of his girlfriend Ruby’s fixed marriage due to his ongoing drug addiction, Sanjay relapses. Kamli convinces Ruby to register marry Sanjay; upset with his intoxicated behaviour, she leaves him. Nargis passes away three days before the release of Rocky, which takes an emotional toll on Sanjay. Sanjay agrees to attend a rehabilitation centre in the United States, and eventually recovers with the help of his father and Kamlesh. On returning to India, he meets with God and beats him for selling him drugs.