Thillai "Cable" Raja Silambarasan is a cable operator born and raised in a Chennai slum. He bemoans his poverty and wants to become rich by marrying his girlfriend Priya. Raja cons her into believing he is well-off and adopts a refined persona for her. He is accompanied by his best friend Seenu and guided by bhajan singer Ganesh. When Priya asks him to buy expensive tickets to a New Year’s Eve gala, Raja is very short of money. After a failed attempt at chain snatching in which he crosses paths with the police, he heads to a hospital with theft on his mind.
Bharath Chakravarthy Bharath Srinivasan, an aspiring rock star from Bangalore, is irresponsible but well-meaning. His mother disapproves of his dream and wants him to become an army officer. When Bharath's band misses their flight to a concert because of him, he drives them to Chennai via road. He and his girlfriend Laasya Vega Tamotia are attacked by religious fanatics and are aided by strangers; this makes him reflect on life. When they arrive in Chennai, their vehicle collides with an auto rickshaw carrying a pregnant woman. Forgoing the concert, Bharath and Laasya rush her to the hospital.
Saroja [Anushka Shetty] is a sex worker at Rani Amma's brothel on the Tamil Nadu-Andhra border. When she discovers that her life is in danger while working there, she escapes to Chennai with her sister Karpooram in the hope of starting a business venture. Hounded by thugs and the police, they are led into a trap. In a fight, Karpooram is mortally wounded, and Saroja carries her to the hospital.
Rahimuddin Qureshi [Prakash Raj] and his wife Zara Rahim [Sonia Agarwal] lost their unborn twins in a Coimbatore riot. Zara becomes pregnant again a few months later, and Rahim goes to Chennai to find his younger brother, who had run away after the riot. Rahim is in repeated conflict with Shivaram, an anti-Muslim police officer who suspects him of terrorism. He is brutally assaulted by Shivaram and admitted to the hospital under close supervision.
Lakshmi [Saranya Ponvannan] is the daughter-in-law of a poor weaver in Thoothukudi. When the weaver cannot repay a loan from cruel moneylender Narasimman, Narasimman kidnaps Lakshmi's bright young son and refuses to release him until the debt is paid. Lakshmi arrives in Chennai with her father-in-law, hoping to sell one of her kidneys to obtain money. She undergoes the surgery and receives money, which is insufficient. Raja steals Lakshmi's money, and she and her father-in-law contemplate suicide.
Conscience-stricken, Raja confesses to Priya and returns the money with some of his own; Lakshmi forgives him. Rahim learns that terrorist leader Mansoor Khan and his gang are planning to kill the people in the hospital. He tries to escape, but when he sees 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 to death. Raja, Bharath, Rahim, and Saroja lead a small group of survivors to an empty room.
Raja and Bharath kill two terrorists, and Bharath takes several bullets in his shoulder to save Saroja. Rahim saves Shivaram from a shooter and encounters his brother, who is part of the terrorist gang. Rahim's brother shoots himself, and Khan reveals himself as a suicide bomber ready to explode. Raja sacrifices himself by pulling Khan and falling out a window; an explosion follows.
In the aftermath, Bharath, who loses one of his hands, is hailed as a national hero. Saroja and Karpooram begin a new life, hoping to find redemption. Lakshmi and her father-in-law pay off Narasimman and give her son a good education. Shivaram apologizes to Rahim and asks for forgiveness; Rahim accepts him as a brother. Raja is mourned by Priya and his community, and Ganesh and Seenu see him as a martyr.
