Thillai "Cable" Raja is a cable operator born and raised in a slum area in Chennai. He bemoans his poverty and wishes to become rich by marrying his girlfriend Priya. He cons her into believing he is well off and adopts a well-bred persona in front of her. Raja is always accompanied by his best friend Seenu and guided by Bhajan singer Ganesh. When he is asked by Priya to buy high-priced passes to a New Year's Eve gala, he finds himself severely short of money. After a failed attempt at chain snatching and crossing paths with the police, he heads to a hospital with theft on his mind.

Bharath Chakravarthy is an aspiring rockstar from Bangalore who is irresponsible but well-meaning. His mother disapproves of his dreams and wishes him to become an Army officer, which he opposes. When his band misses their flight to a live concert because of him, he takes them to Chennai via road. En route, Bharath and his girlfriend Laasya are attacked by religious fanatics, but are aided by strangers, which causes him to reflect on life. They finally arrive in Chennai, but their vehicle collides with an auto rickshaw carrying a pregnant woman. Sacrificing their concert, Bharath and Laasya rush her to the hospital.

Saroja is a prostitute working at Rani Amma's brothel at the Tamil Nadu-Andhra border. When she discovers that her life is constantly in danger while working there, she escapes to Chennai with her sister Karpooram, a eunuch, in hopes of starting her own business venture. On arrival, she is hounded by thugs and policemen, ultimately being led into a trap. In an ensuing fight, Karpooram is mortally wounded. Desperate, Saroja carries her to the hospital.

Rahimuddin Qureshi and his wife Zara had lost their unborn twins in a communal riot in Coimbatore. When Zara becomes pregnant again a few months later, Rahim heads to Chennai to locate his younger brother, who had run away following the riots. There, he comes into repeated conflict with anti-Muslim officer Shivaram, who suspects him of being a terrorist. Despite his claims of innocence, Rahim is brutally assaulted by Shivaram and is admitted in the hospital under close watch.

Lakshmi is the daughter-in-law of a poor weaver in Thoothukudi. When the weaver is unable to pay back a loan to a cruel moneylender Narasimman, the latter kidnaps Lakshmi's young son, a bright student, and refuses to release him until his debt is cleared. Lakshmi arrives in Chennai with her father-in-law, hoping to sell her kidney to obtain the money. After initial hassles, she undergoes the operation and receives the money, although it is still insufficient. At that point, Raja enters and steals the cash from her, ignoring her pleas. In a state of despair, Lakshmi and her father-in-law attempt suicide.

Struck by his conscience, Raja is unable to continue his plan. He admits the truth to Priya and returns the money, even adding in some of his own money to give up, thus gaining Lakshmi's forgiveness. Meanwhile, Rahim discovers that terrorist leader Mansoor Khan and his gang are planning to kill all the people at the hospital. Rahim tries to escape, but on seeing Bharath wheeling in a pregnant woman, he is reminded of his wife and offers to help them. The terrorist strike begins, and several people are shot dead. Raja, Bharath, Rahim, and Saroja lead a small bunch of survivors to an abandoned room.

Raja and Bharath fight and kill a terrorist one-on-one, with Bharath sustaining multiple bullet wounds to his shoulder in order to save Saroja. Rahim saves Shivaram from a shooter and comes face to face with his brother, who is part of the terrorist gang. When confronted, Rahim's brother shoots himself. Just then, Khan reveals himself to be a suicide bomber, and primes to explode. Raja sacrifices himself by pulling Khan and falling out of the window, followed by the explosion.

In the aftermath, Bharath has lost one of his hands but is alive; he is hailed as a national hero. Saroja and Karpooram head toward a new decent life, hoping to find redemption. Lakshmi and her father-in-law manage to pay off Narasimman and give her son a proper education. Shivaram apologizes to Rahim and asks for forgiveness, which he grants and accepts him as a brother. Raja is mourned by the people in his community and Priya, while Ganesh and Seenu hail him as a martyr.