Lallan Singh (Abhishek Bachchan) is a goon, originally from Bihar but settled in Kolkata, West Bengal because his brother Gopal Singh (Sonu Sood) has left him alone and he had no option of earning back home. He loves, marries and abuses his wife, Shashi Biswas (Rani Mukerji).
Michael Mukherjee (Ajay Devgan) is an influential student leader who wants politicians like Prosenjit Bhattacharya (Om Puri) to keep away from college elections. Michael is in love with his neighbor Radhika (Esha Deol) who lives with her uncle and aunt.
Then there is a 20 year old boy named Arjun (Vivek Oberoi), carefree and spoiled son of an IAS officer. He wants to relocate to the U.S. for a better future. He falls in love with Mira (Kareena Kapoor), whom he just met. Arjun asks Mira for coffee and takes her to the beach and realizes that Mira loves him back.
One day, Arjun and Mira get into a quarrel on the road and Mira gets into an auto. Arjun gets lift from Michael to catch up with Mira, who is going that way. Suddenly, Michael is hit by a bullet, and he is saved by Arjun. After talking to Michael, Arjun changes his mind and wants to be a politician. Prosenjit is worried when he hears news of students standing in the election. He uses every possible way to get them out of politics. First he provides scholarship of a prestigious foreign university to Michael. When Michael refuses the bribe, he orders his goon Gopal Singh to take control. Gopal beats some students but faces very strong retaliation from Michael and his fellow students. After that Lallan Singh takes charge and kills Gopal. He kidnaps Arjun and other candidates. However, they escape with the help of Lallan Singh's ally. Lallan follows Arjun and beats him up. While running, Arjun calls Michael for help. He comes to rescue Arjun at Howrah Bridge. A fight ensues between the 3 men but Lallan overpowers Arjun but is defeated by Michael who chooses to spare him and leave him for the police.
Lallan is handed to the police. Michael wins the four seats he and his fellow students have contested for. Shashi leaves for her hometown while Lallan remains in prison. Michael, Arjun and two friends enter into politics.