Maa Kasam is an action drama. The movie revolves around the treasure owned by Thakur and his family. When an ex-convict learns about the treasure, he seeks out to claim it, but he learns that the map to the treasure is in a ring, and in the process to get the ring, he kills Thakur and his son, but couldn’t find the ring. Later, he even murders his own wife, and his dying wife takes his son, Dharma (Mithun Chakraborty), to Thakurain and requests her to raise him like hers. Dharma grows up under the care of Thakurain and is a hardworking and kind man, unlike his father. Years later, Balwant returns to claim the treasure, but this time he’ll find himself against his son. In this father-son’s clash who will win?