Nijam (Truth) is an Action based movie. In which, Reddy (Jayaprakash Reddy) is a powerful mafia leader whose right hand is Devudu aka Devadaya Sharma (Gopichand). Devudu has a lover called Malli (Raasi). Reddy - who also like Malli - takes her to the bed, which is not liked by Devudu. In the process, Devudu kills Reddy and he becomes the leader of the mafia gang.
Venkateswarlu (Ranganath) is a fire officer. In an incident, Devudu sets the market place afire and Venkateswarlu rescues it with his fire fighting and at the same time Venkateswarlu slaps Devudu, as he continues throwing kerosene at the market place. Devudu holds grudge against Venkateswarlu and sends him to jail on a framed charge of murder.
Seetaram (Mahesh Babu) who is the son of Venkateswarlu tries to rescue his father from the jaws of police. But in the process, everybody starts asking him for money to do the work. At the end of the day, the police officer kills Venkateswarlu.
The rest of the story is about how Seetaram takes revange on the people responsible for the death his father with the help of his mother (Talluri Rajeswari).