Gautham, a man with special needs, comes to Pondicherry. Hema, a carefree woman, befriends him and with the help of her father, who is a psychologist, unravels his horrific past life.

On the search of his missing brother, Vasu finds out that Vel is his twin brother and risks his life to clear his brother's problem given by Sakarapandi an X-MLA .

Siva is an honest police officer who was brought up by the judge Sathyamoorthy, when his mother died. Sathyamoorthy has two sons : Aravind and Raja. The influential smuggler Mudaliar often clashes with Siva and Sathyamoorthy. Siva and the jolly college student Priya fall in love with each other, later they get married with Sathyamoorthy's blessing. One day, Raja rapes Mudaliar's daughter. The next day, Raja is found dead and Siva conducts the investigation. Ramesh admits to his father Sathyamoorthy that he killed his younger Raja. Sathyamoorthy decides to protect Ramesh at all costs while Siva wants to send Ramesh to jail. What transpires later forms the crux of the story.

Kottai Vaasal is a 1992 Indian Tamil film, directed by Selva Vinayagam and produced by Mohan Natarajan and Tharangai V. Shanmugam. The film stars Arun Pandian, Sukanya, Saranya and Goundamani in lead roles. The film had musical score by Deva.