Raja (Rajinikanth), an expert thief is in love with Radha (Madhavi), a disco club dancer-cum-singer, who is unaware of Raja’s profession. Meanwhile an evil brother-sister (Vijayakumar-Anuradha) duo is bent on seeking vengeance from Crime boss Sudharshan, who cheated and siphoned Jwaala’s money. The duo hire Raja to break into Sudarshan’s treasury and perform the heist. But was caught by a jovial-cum-shrewd Inspector Rajasingam (Sivaji Ganesan) and awarded 2 years imprisonment, which shocks and devastates Radha.

Gajendra (Vijayakanth), an orphan, is adopted and grows up under Azhagarsamy’s (Sarath Babu) family care. Azhagarsamy considers Gajendra like his own son. Kasthuri (Flora), Azhagarsamy’s granddaughter, falls in love with Gajendra. Gajendra takes of a mentally ill girl Indhu (Laya). The rest of the story is about why he took care of her.

Sachein (Vijay), a carefree and happy going guy joins a college in Ooty and falls for Shalini (Genelia) immediately on seeing her in first sight. Shalini studies in the same college as Sachein and is considered a popular and beautiful student, while also being a short tempered and arrogant girl with an upper-middle class status. Sachein comes to know all of this information about her from Arnold aka Ayyasamy (Vadivelu), who is a guy that studies in the college for about nine years and keeps studying there because he thinks that students should give their respect to their college professors, while also informing Sachein, that there are so many boys trying to impress her. This makes Sachein take a different route and he starts mocking Shalini in front of her, which irritates her. Slowly, they both become good friends, after Sachein saved her father in a bike accident. Santhanam (N. Santhanam), who is another student in the college also loves Shalini. But, he feels jealous seeing her and Sachein being good friends and decides to separate them. Santhanam writes in one of the walls of the college, that Sachein loves Shalini and this angers Shalini, as she misunderstands that only Sachein has done it. Shalini shouts at Sachein, but Sachein informs Shalini, that he is so outspoken and does not want to write in the college wall to convey his love, which makes Shalini realize her mistake.
But to her surprise, Sachein informs that, although he has not written it, but the content present on the wall is true which means that he is in love with Shalini. This again angers Shalini and she shouts at him that she considered him only as a good friend and that she wasn’t in love with him. Later, Shalini overhears Sachein challenging Santhanam that Shalini will convey her love within the next thirty days, as their college years will be completed by then. Shalini challenges Sachein that she will never fall in love with him.
Manju (Bipasha Basu) is also from the same college and she likes Sachein. Shalini gets jealous when she spots Sachein and Manju together often. But Manju informs Shalini that Sachein loves Shalini so much and asks her not to hide her feelings, as it is very evident that Shalini too likes Sachein. This makes Shalini realize her love towards Sachein. Sachein comes to know that Shalini’s parents have arranged a wedding for her and he meets Shalini on the last day of their college and says that he has lost the challenge and he will be leaving Ooty tomorrow. But Shalini hides her feelings towards Sachein and she plans to propose her love the next day as she wants to win the challenge by not conveying her love within the 30 days.
On the 31st day, Shalini is excited and goes to propose Sachein. But suddenly, she meets Gowtham (Raghuvaran) on the way, who is Sachein’s father. Gowtham is a billionaire, in which this fact makes the entire college be surprised that Sachein is the only son of a rich business tycoon, as Sachein always stays very simple and down to earth. Now Shalini feels bad, that if she proposes her love towards Sachein at this moment, then he might misunderstand that she decided to marry him after knowing that he is so rich and decides to stay calm. Sachein leaves to the Coimbatore International Airport in Coimbatore and Shalini also follows him. In the airport, Shalini could not control her emotions and proposes to Sachein. She also revealed that it is her ego that didn’t let her convey her love during the last thirty days. Sachein feels so happy and the couple are united.

Three amateur thieves plot to kidnap the young son of wealthy Chettiar (Santhana Bharathi) from school. They do a trial run. However, on the eve of the kidnap, the guy whose job is to operate a crane in this plan is hospitalized. The services of Avinasi a.k.a. Mumbai Xpress (Kamal Haasan), brother of Kovai Sarala, a deaf stuntman performing daredevil bike acts, is roped in. Twists and turns take place where the other two gang members are hurt, and invariably, our Mumbai Xpress is left to perform the task all by himself. He kidnaps a wrong boy Daddu (Hardhik), the illegitimate son of Ahalya (Manisha Koirala) and police officer Rao (Nassar), but manages to get a huge ransom from Chettiar by default. A brawl takes place between the original kidnap planners – Chidambaram (Pasupathy), Johnson (Vaiyapuri), and Avinasi – in handling Ahalya’s child, but Avinasi delivers the child unhurt to his mother.

Two passionate people with dreams swap places accidentally by fate and their common key to get back their lost life is to defeat the antagonist through the girl whom he wants dead since she can foresee the future.

In 1279 A.D., the downfall of the Chola dynasty seems imminent as the Pandyas drive the Chola people out of their kingdom in southern India. To escape them and save the life of his successor the Chola emperor sends his son along with the Chola people to a secret territory. The refugees take along an idol sacred to the Pandyas, angering them. To capture the escaped Cholas and the stolen idol, the Pandyas extend their invasion to unexplored territories but cannot find them.
Centuries later, in 2009, Indian archaeologists continue searching for the existence of the lost Chola group based on clues left by the ancient Pandyan warriors. All archaeologists who attempted to search for the secret land have disappeared. Archaeologist Chandramouli is the most recent person to have gone missing suddenly.

The film starts with Ashok Kumar aka AK (Ajith Kumar) setting bombs in three places and informing the police about them. Before the police arrive, the bombs are set off. AK, along with his lady love Maya (Nayanthara), threatens her old college mate hacker Arjun (Arya), who is forced to hack one system after another. AK then threatens Sriram Raghavan (Aadukalam Naren) by trying to kill his child so that he can extract the truth about black money. AK then murders Sriram. Arjun, who is irritated by the things happening around him, complains about AK’s misdeeds to Inspector Prakash (Kishore). When AK gets closer to achieving his goals, Arjun gives him away to the police, and both are arrested. Arjun is later released after his true identity is revealed.

A cop lands in Kerala following a lead over a girl’s kidnapping and learns about a sex trafficking racket. As he pursues the case and tries to save the girls, his own daughter is kidnapped.

A brilliant scientist builds a humanoid robot to protect mankind, but things go awry when human emotions are programmed and inner turmoil causes the robot to act against him.

The life of a young man and his struggles against the privatization of education.

Ko 2 revolves around a man who kidnaps the chief minister of the state and the mystery over why he does so.

As a child, Paari (Atharvaa) lost his father who tried to stop the war between his native and neighboring village as they fought over sharing a pond water. Years later, Paari is a young man who returns from Singapore but the battle between two villages is still on. Mean while, Paari is in love with Thamarai (Anandhi), daughter of rich village man (Lal) who also owns the pond and is adamant not to supply water to the nearby village.