A man (Amitabh Bachchan) is found wounded on railway tracks and when he awakens he has no memory of who he is and doesn't remember anything about his life. Six years later he is living with a wealthy couple and is now named Naresh Dutt. One day he begins to regain his memory when he watches a film and realizes that the actress in the film is related to him somehow. It is then that he discovers the actress in the film is none other than his wife Rekha Roy (Rekha). He finds out that she is now a very successful film actress changing her name to Sunita Devi and her manager is none other than Ranjeet Malik (Prem Chopra) who used to be his best friend. In flashbacks he remembers that his real name is Amit Roy and Ranjit was the one who attempted to kill him six years earlier by throwing him off the train he was traveling on with Rekha. Amit also discovers that his young son who is now 10 years old has been sent to a boarding school and sets out a plan to regain custody of his son...

Four slackers and con-men namely: Boman Contractor, who lives a wealthy lifestyle with his eccentric dad, Nari, who loves his antique car more than his son, and asks his son to leave when he damages the car; hot-headed Aditya and dim-witted Manav, orphaned brothers; and Deshbandhu Roy, a trickster who wears a magnetized belt; share a room with a lenient landlady, who eventually gives up on them and kicks them out. After a number of con tricks, the group are arrested by the Police, but released in the countryside. At this point they witness a car plummet down a cliff, with it's sole occupant, Bose, an underworld don, who, before dying, tells them that he has hidden 10 Crore Rupees in cash in the St. Sebastian's Garden, Goa, and if they find it, it is their's to keep. The group race toward Goa in Contractor's stolen car, little knowing that their plans will soon be foiled...

Delhi-6 attempts to exposes the dual face of a person. We all live in today's world pointing a finger at the other person for all that's going wrong around us. Looking for the devil who can be blamed. In reality the devil resides within us. The story is told dipping the pen in the ink of "chaos" the color of which is black. It's a story of a young American boy "ROSHAN" of Indian origin, who comes to India for the first time, to drop his ailing grandmother. She wants to die in her own soil, and so prepares for her own death. In America having lead a very western lifestyle Roshan wasn't aware of the sites and smells, the food and culture, the religion and beliefs, that an Indian society is filled with. After coming to India he interacts with his grandmother's neighborhood and seamlessly dissolves in as if one of them. Little does he know that the endearing people including his grandmother have another face that feeds the devil within...