Property Issues

Hello. My grandfather has 6 children. My father is the 5th child. And he has 3 brothers and 2 sisters. In my community, the father stays with the youngest son and the youngest son takes care of the elders. Due to this, the youngest son acquires extra land when the father devolves the land. The females do not acquire any ancestral property. But my aunts forcefully converted the ancestral property brainwashing my grandfather. My father has paid for all the expenses of my grandparents. Both my grandparents expired. All the sisters were married off when my grandfather was alive and all of them received fair share of dowry long back. The youngest of the sisters has 2 handicapped children. They have good amount of land resources at their in-laws. She is using these handicapped children to file false complaints against my father. She is doing the same with my father's younger brother. She is targeting both and has recently destroyed the cattle shed recently and caused a lot of destruction. Now she is sending notices through lawyers. These handicapped children are roaming different offices creating nuisance and forcing the officials to do work in their favor like transferring the properties.