Twin brothers, Vasu and Vel, get separated at birth and grow up in different families. One becomes an officer while the other turns into a rough character.

The film starts with Kailasam (Ravi Kale), the somber bigwig who is performing the last rites of someone dear to him, but the appearance of Kottai (Jiiva) (first in the chaotic Koovagam festival and later atop a Veeranam pipe) swinging a scythe maniacally sets the tone for the rest of the film.
Cut to the flashback a few months ago: In Ramnad, Kottai’s mother (Saranya Ponvannan) is cutting down logs and boasting about her son: he is a god who deserves to see the outside world and derive its benefits. Kottai journeys to big bad Chennai in company with Vellaiyan (Ganja Karuppu), who dances with every Karagattam dancer on the roadside, makes lewd jokes, and appears to have only one thing on his mind. They end up at the massive home of Kailasam, the local terror who slices up people whenever he can. However, our heroes are unaware of the fact.

A man, surrounded by birds, hangs himself to death at a cell tower. Elsewhere, the scientist Vaseegaran introduces Nila, his new humanoid robot, to a group of students. A little later, a student’s smartphone starts flying all on a sudden, exhibiting avian characteristics. Before long, cell phones all over Chennai begin to fly away, leaving the city in chaos. At an emergency council meeting initiated by the government, Vaseegaran enunciates that it is beyond conventional science to fight what he considers a fifth force, and proposes reinstating Chitti, which was dismantled in 2010. But Dhinendra Bohra, who lost his father, Professor Bohra, to Chitti’s anger,[a] opposes, and the council decides to seek help from the military, thereby vetoing Vaseegaran’s proposal.
The growing stream of cell phones leave havoc in its path, killing a mobile phone wholesaler Jayanth Kumar, a transmission tower owner Ranjit Lulla and the state’s telecom minister Vaira Moorthy. To prevent further damage, S. Vijay Kumar, the Home Minister, unofficially gives Vaseegaran permission to rebuild Chitti. Chitti traces the mobile phones, which have taken the form of a giant crow, and they fight, during which Chitti’s battery power is depleted and it starts searching for a power source amongst three huge signal transmitters. To Chitti’s surprise, the crow is unable to penetrate the field of transmitters and suffers damage while attempting to do so.

When Gopal, a young man, is adopted by Lingam, an ageing gangster living in Madurai, he goes to any extent to protect Lingam from his enemies and the police.

Kannan (Mammootty) is a sincere district collector. A female leader of a major political party is kidnapped by terrorist Veeraiyan (Nassar), and he promises to return her back if his injured brother Arasappan (Napoleon) is treated well and brought back safely. The government agrees to this condition and asks Kannan to look after Arasappan. At first, Arasappan hates Kannan and his family as Kannan works for the government against whom his brother’s group is rebelling, but the kindness shown by Kannan’s wife and mother change his attitude. Just when he was about to turn over a new leaf, a bad thing occurs. The police team, without taking the necessary orders from Kannan, go to the forest and attack Veeraiyan’s gathering. This angers Arasappan, but he was restrained by Kannan. the police accuses Kannan of having links with the terrorists as Arasappan ran away from his house and Kannan condemned the police action; hence, they arrest Kannan’s wife and mother (Kannan ran away to find Arasappan). Hearing this sad news, Arasappan surrenders to the police as he did not want them to suffer for him, but the police do not spare him despite his surrender.

An elderly Malaysian man goes ballistic and kills several Indian officers in a span of 5 minutes at the Indian Embassy in Kuala Lumpur, Malaysia, before collapsing. A tattoo of a love symbol is present at the back of his neck, leading RAW officials to conclude that it is the handiwork of a criminal scientist named Love, whose identity and whereabouts are unknown to anyone except Akhilan Vinod (Vikram), a suspended RAW agent whose wife Meera George (Nayantara), a leading computer analyst at RAW, was killed by Love 4 years ago. RAW chief Malik (Nassar) tracks down Akhilan and convinces him to join the investigation. On viewing the video footage of the attack, Akhilan comes to the conclusion that the elderly Malaysian man had taken a mysterious performance-enhancing drug which allowed him to attack the Indian officials and decides to investigate the matter further in Malaysia. Since Akhilan is under suspension, Malik assigns him as a deputy to a junior RAW agent Aayushi (Nithya Menen), who is officially assigned to handle the case, and the two of them leave for Kuala Lumpur.

The son of an egoistic businessman falls in love with an egoistic girl and has to convince her egoistic mother in order to marry her.

Chandru (Arya) and Bigilu (Lal) are close friends. Chandru is an expert auto driver and racer, while Bigilu is a mechanic expert at customizing autos to run at the dream speed of 130 km/h. Pichchai aka Son of Gun (John Vijay) is the chief of a rival group who wants to outsmart the duo. Chandru, the race champ, tries to settle the dues for his auto through a race, which is almost a cakewalk for him. He and Bigilu challenge Son of Gun to a race, and a date is fixed. Bigilu, meanwhile, introduces Chandru to his sister, who runs a biriyani shop. Chandru is attracted to her daughter Rani (Pooja), and woos her. The affair grows stronger, and the two end up having sex. However, Chandru is not interested in long-term commitment and tells Rani, who curses him and moves away. On the D-day, Chandru is distracted by the memories of his love affair and loses the race and his auto. Later, Bigilu comes to know about the affair. The subplot of a smuggler’s search for missing pearls adds flavour to the proceedings. The unpredictable and fun-filled climax puts everything in order.

A lawyer ends up killing the son of a gangster and the latter swears revenge.

A disillusioned everyman, frustrated with the corruption he sees all around him, develops multiple personalities in order to restore justice.

An Indian soldier is assigned a mission to eliminate his former mentor, who has gone rogue.

Deva (Suriya) arrives at the Chennai International Airport after running an errand for Arumuga Dass (Prabhu Ganesan) of smuggling pre-release unlicensed movies on DVD. The two leave for their hideout and instruct Dilli (Karunas), a hearing-impaired assistant of Dass, to make copies of the DVD. Just when police crews arrive into their vicinity, Dass informs Deva and the rest to leave. Deva tells the others to leave while he quickly sets up the burning process. Deva also leaves the hideout just in time. However, the police officers arrive at the hideout, only to see the burning process of the DVDs complete. The police then seize the DVDs and computers. The inspector, who was a friend of Dass, tells him that he can close the case if one of Dass’s men agrees to the crime. Deva attempts to go, but another man, Chitti (Jagan), who had no affiliation to them volunteers, takes the blame. Later, Chitti joins Dass’s group and befriends Deva.