Duniya is an action revenge drama that follows the story of an honest and hardworking man named Mohan Kumar (Dilip Kumar), who works as a general manager for a shipping company owned by his friend Dinesh (Pradeep Kumar). However, his life takes a turn when Dinesh gets killed mysteriously, and Mohan is framed for the murder that was committed by three of his colleagues who work in the same company. On the charges of murder, Dinesh is sentenced to jail; however, he vows to avenge the humiliation when he completes his time in prison. Will Dinesh succeed in his mission and unite with his family?