Aleyar Alo (1970)

Deep Narayan, a wealthy and noble man, is killed by his greedy brother Anugraha, who seeks to inherit his property if Deep dies childless. Unaware that Deep's wife, Shree, is pregnant, Anugraha proceeds with his plan. Before dying, Deep confides in his manager Chandrakanta, who vows to protect Shree. Shree gives birth to a son, Pradip, who grows up to take charge of the family business and falls in love with Shikha. When Shikha learns she's adopted, Pradip also discovers he isn’t Shree’s son. It's revealed that Chandrakanta had switched the babies, and Shikha is Shree’s daughter, while Pradip is the son of Deep’s employee, Mr. Sridhar. In a selfless act, Sridhar dies while saving Pradip during a rescue in the coal mines.