Nandha is story about a young man from a juvenile jail coming back to a society and his family he had left many years ago. It is about a battle of love and life, and how a misfit tries to fight to fit into the usual social circus, a fight to earn his mother’s love, and a fight to live the second chance he has given himself. The story takes place in the town of Ramanathapuram.

Nandha (Surya) is sent to a rehabilitation center for murdering his father as a boy after witnessing his father’s infidelity and abuse towards Nandha’s mother (Rajashree) when she finds it. He returns home to his mother, who is deaf and mute, and his sister (Sheela), who are still in a state of shock after what has happened to their family.

He decides to get a new life by trying to give himself a college education. Having the record of being an ex-convict, he finds it difficult to get a seat in a college. He meets Periyavar (Rajkiran), a very rich disciplinarian who runs an arts and science college with an iron hand. Periyavar’s forefathers were the kings of the Ramanathapuram kingdom and fell in line in with the Britishers. After independence, all of their palaces and titles were taken by India’s government, but a lot of other material wealth was in their hands. He still thinks himself a guardian of people and helps a lot of poor people. He even goes to the extent of providing justice when law and police can’t or won’t.

Periyavar develops a soft corner for Nandha and guides him like his own son. Kalyani (Laila), a Tamil exile from Sri Lanka, meets Nandha and both fall in love. Meanwhile, the villain Saravanan asks Periyavar, who also helps Sri Lankan students in his college a lot, to aid an antisocial element, but Periyavar refuses outright.

Periyavar’s son-in-law agrees to help Saravanan. Meanwhile, Periyavar falls sick and gets admitted in the hospital. Nandha stays around to look after his mentor and guide. Fearing what he has done might be out in the light, the son-in-law pulls out the oxygen tube of Periyavar in the hospital when Nandha is not around and blames Nandha for murdering his father-in-law. Nandha, having to deal with the pain of losing the only man who gave him a second chance to live, also struggles the fray of being convicted of murder once again and he chooses to kill Periyavar’s son-in-law in the court campus. The case is dismissed due to the lack of evidence. Finally, he is acquitted as there are no eyewitnesses to the murder.

After being acquitted for Periyavar’s son-in-law’s murder he returns home. His paranoid mother, who still believes that her son still has murder instincts, waits at home to feed a meal, which she has poisoned herself. He finds out that the food is poisoned when he eats it, but continues to do so with a satisfaction that he is being fed by his mother. He dies in his mother’s lap and when his sister and Kalyani come out to see what has happened, they realise that both mother and son are dead.