Ancestral property dispute

My father (66) died due to cardiac arrest last year, its been hard both on my mom and me, we are emotionally and mentally down. My father took care of our ancestral property for 40 years in our native place and also he bought some farming land next to ancestral farming land. Since my dad's death his brothers are harassing my mom and me emotionally and pushed my mom to attempt suicide (I saved her from that). The elder brother destroyed one of two ancestral house and built a house there, the other house keys(my dad lived here for 40 years) are with me. The brothers knew this info and are harassing me verbally saying : hand the keys over or else I will break the house open and you cant do anything about. They started farming in my father's farm land without my knowledge and are mocking us saying you can't do anything about. I am in immense pain and agony right now. Financially its hard for me too, and I dont have any support from anyone in my father's side (i expected this) and they are treating my mom so bad its hurts me alot. I would greatly appreciate any advice on how to tackle this and cut ties from this extended family. To be precise how to handle the ancestral properties partition(the properties are in our native village) and save my father's land.