The orphaned Laxman Singh Bisht (Salman Khan) and his younger brother Bharat Singh Bisht (Sohail Khan) are inseparable. Laxman is a naive, simpleton man who understands things slowly and hence people in his village have nicknamed him Tubelight. Local bullies never leave a chance to harass him whenever they find him alone. His younger brother Bharat protects him like a shield. Both brothers share enviable bonding. They have been together since their childhood and cannot live without each other.

But one day, Banne Chacha (Om Puri) advises Bharat to join Army so that he could take care of his elder brother in a better way. He complies and joins the Indian Army, leaving Laxman alone in the village. Soon, Bharat is sent across the border to fight in the Indo-Chino war of 1962.

Months pass by, but Laxman is unable to find the whereabouts of his brother. Soon, he comes to know that he brother has gone missing in the war. Laxman feels helpless, but he does not lose his hope. He vows to find his brother no matter what. However, he has no one to help him in his endeavor except his faith.