Ghulam is the story of the young man named Siddu (Aamir Khan) who grows up in a low-class locality of Mumbai. Orphan, uneducated tapori and the neighbourhood boxing champion besides his name Siddarth Marathe the only thing Siddu has of his own is the elder brother Jai (Rajit Kapoor) who looked after and provided for him all the love and care Jai got educated and worked for the local Don Raunak Singh (Sharat Saxena). Keeping Ronnie's Account and the brain behind Ronnie's plan. The rich girl Alisha (Rani Mukherji) comes into Siddu's life like a dream too good to be true. Then Siddu meets Hari a social worker who reminds the Siddu of his dead father who like Hari talked about fighting injustice and oppression. Hari pleads the basti people to stand upto the tyranny and oppression of Raunak Singh. Hari is a problem for Ronnie. Ronnie kills Hari using Siddu as a bait. Siddu comes to know that Hari was Alisha's elder brother Siddu vows to complete the mission Hari had began which brings him to crossroads with his own brother and Ronnie. He decides to give back the Basti people their list dignity and self-esteem. Ronnie kills Jai and comes after Siddu. Fatima (Migta Vashisth), the lawyer helps Siddu to bring Ronnie to court. The rebel is born Basti Ronnie's kingdom and Siddu goes to Basti to face to face with the tyrant. Siddu rises to the occasion to became the real man that his Baba wanted him to be.