Parvathi (Latha) is a rich and arrogant woman who leads her life with her three sons – Kandha (Prabhu), Kadamba (S.Ve. Sekar) and Kathirvela (Vivek). The sons are very obedient towards their mother and they run a restaurant in Chennai. Parvathi also had a daughter (Bhuvaneshwari) who married Vadivelan (Vadivelu), a barber following which Parvathi disowns her daughter. Vadivelan decides to teach a lesson for Parvathi. He understands that Parvathi’s sons are in love with girls from economically backward community and sets a plan to get them married against Parvathi’s wishes. Kandha is married to Rubini (Roja), Kadamba to Ragini (Kovai Sarala) and Kathir to Rohini (Nirosha).

Bharat has paranoid schizophrenia however it is revealed only in the end. In the first half he is a good Samaritan, a real estate guy who helps people from land grabbing mafia. In the second half however he is shown killing Dr Srinivasa Iyengar (Nasser), a police inspector Mahesh Deshpande and a minister.

Gautham suffers from a psychological disorder that causes confusion and memory issues. He is sure that his parents were killed, but is unable to remember the names or identity of the killer.

Sitharam (Arjun) is a well respected auditor who lives with his PA Muthuswami (Anu Mohan) in Chennai. Although being a short-tempered and tensed person, Sitharam is very good at heart who helps the people in need. He soon meets and falls in love with Kalyani (Sonali Bendre). After a couple of meetings she too falls in love with him by seeing his good nature.
But Sitharam faces problems in the form of another loving couple, Akash (Suchindra) and Akhila (Ruchita) due to an argument between Akhila and Akash and Akhila acts as Sitaram’s fiancé so that she can get rid of Akash just before he proposes to Kalyani. Kalyani, being an innocent, believes her words and goes away from Sitharam. Hence, Sitharam becomes the main antagonist of the film to make the lives of Akash and Akhila the living hells.

Based in Kancheepuram, Surya/Arjun makes a living as a con-man on the North Zone, and is assisted by his girlfriend, Baby; while the South side is presided over by Pashupati. When a Kolkata-based contractor hires the latter to kill District Collector Jaianand/Kishan, Surya decides to defend him – this results in his finding out that Jaianand is his look-alike. Jaianand’s terrified fiancée, Shanupriya, then hires Surya to not only protect but also impersonate Jaianand – a move that will drastically change everyone’s lives – especially when Kishan refuses to let anyone take his place.

Jaihind tells the story of the journey of five people, linked by one man, who fights for childrens’ rights to education. Parvathi (Yuvina Parthavi), from a very poor family background, gets an admission into one of the most affluent schools in the city. However, the man of the house is forced to sell one of his kidneys in order to pay the exorbitant school fees. They still are unable to raise nearly enough money for the school, and they finally give up and commit suicide. This disturbs Abhimanyu (Arjun Sarja) deeply, and the computer service engineer becomes a hero overnight, by propagandizing a solution for education costing so much. Abhimanyu suggests that all private schools be nationalised, which will compel them to offer services at very little fees compared to that being collected now, while still ensuring that the quality of education is not compromised. This is bad news for the private school owners, who make a business out of educating children. Abhimanyu is targeted and pushed to extremes for his ideas. He is put behind bars and has people conspiring to murder him. How he succeeds in his mission, despite all this, forms the crux of the movie.

A group of four youngsters get on a train, they are then scolded by a quick-tempered stranger Ananthakrishnan (Prakash Raj), he tells them that today’s young people are immature and good-for-nothing. The friends are about to prove him wrong.

Trained killer Ladybug wants to give up the life but is pulled back in by his handler Maria Beetle in order to collect a briefcase on a bullet train heading from Tokyo to Morioka. On board are fellow assasins Kimura, the Prince, Tangerine, and Lemon. Once on board the five assasins discover that their objectives are all connected.

A young woman is murdered right in front of a police station. The inspector at the station suspects her boyfriend, a private detective, who claims he is innocent.

Two police trainees witness the kidnapping of a girl one night on their way home. Unable to get help from the local police and determined to rescue the girl, they set out on their own amateur investigation.

A young man who gets easily scared is possessed by a ghost that is seeking revenge.

Chitra (Nayantara), a medical student and her friends are working on a project about the human brain. She wants to investigate the curious case of Sanjay Ramaswamy (Suriya), a (former) notable Chennai based businessman, who is reported to have anterograde amnesia. Her professor denies access to Sanjay’s records as it is currently under criminal investigation. Chitra, nonetheless, decides to investigate the matter herself.
Sanjay is introduced as he brutally murders a man. He takes an instant picture of the man, and writes on it “done”. Sanjay has anterograde amnesia; he loses his memory every 15 minutes. Sanjay uses a system of photographs, notes, and tattoos on his body to recover his memory after each cycle.