When a young boy Saravanan is killed by rowdy — and aspiring politician — Dhanasekaran (Sayaji Shinde), his distraught mother (Vinaya Prasad) is ready to kill herself. She is stopped by Mani Shankar (Vijayakumar), who promises her that her son will be reincarnated and meet her 30 years hence. The only condition is that the mother must remain inside Vaitheeswaran temple, praying to be reunited with her son. 30 years later, her wait catches the attention of the public, who are curious to see if Saravanan shows up. Dr. Bala (Sarathkumar), who has no belief in reincarnation, wishes to treat her while Dhanasekharan, who is now a politician and eyeing the CM seat, knows that Saravanan’s arrival could derail his plans. Armed with a computer-generated photo of how Saravanan would look like now, Dhanasekharan and Bala go looking for him, when Bala realises that he is indeed the reincarnation of Saravanan. What happens next forms the climax of the story.

Jambhavan movie is about Velan (Prashanth) who is a responsible son of a village landlord (Vijayakumar). Adored by the villagers for his good deeds, Prashanth gets a shock when Vijayakumar informs that he is his foster son.A shocked Velan sets out on a mission to know about his past. He reaches Chennai and comes to know that his family members were killed by a dreaded gangster Deva (Vijayan). He had then vowed to kill him and his gang. In the name of Jambhavan, he starts to kill rowdies in the society.Suffering an injury in his head, Velan loses memory and is later adopted by Vijayakumar. He comes to know that his job was just half-done. The rest is how he puts an end to Fefsi Vijayan and his men coming to Chennai.