The theme of Suraj in a nutshell is - "Truth shall Prevail".
Ram Singh, a loyal retainer of King Sangram Singh, is unwittingly wronged by his master. Ram Singh vows vengeance ! And his vendetta knows no bounds. He schemes to undo what the Gods did.
Sangram's infant son is kidnapped by Ram Singh and the latter's own son of the same age is planted in the palace as the prince.
When the two infants grow up, the real prince has been turned by Ram Singh into a daredevil bandit named Suraj ! He has been tutored by Ram Singh to hate his real father, the king. Ram Singh's aim is that Sangram should someday hang his own son as an outlaw while Ram Singh's son should succeed to the throne and marry princess Anuradha.
Man proposes and God disposes. It is much worse when man yearns to dispose what God himself proposed. It is not prince Pratap who wins princess Anuradha's love - but the bandit Suraj. Suraj who believes Ram Singh to be his father has turned out to be a brave and kind young man. On the other hand Ram Singh's real son, though brought up in the palace as prince Pratap has turned out to be a villain and a tyrant. Anuradha knows that Suraj hates royalty, so to keep his love she masquerades as a commoner. The same commoner is passionately desired by Pratap who abducts her forcibly.
Naturally, there is a clash between Pratap and Suraj - and what a clash ! On one side there is all the might and armies of a princely tyrant - on the other side, there is the indomitable courage of a lion - hearted bandit. All the while Ram Singh vilely schemes that his real son should triumph - but, only truth and justice triumph in the end !!
(From the official press booklet)