My grandfather sold my father's house that he build with his money with my grandfather's clarification but now he sold the house

My grandfather have two properties one in rajasthan another 2000 sq.ft and one in Assam in raj. My father build a house on this land in about 750 sq. Ft and in Assam there a house my grandfather built and 3 shops. In Assam in 3 of the 2 shops my father and grandfather started a business in which grandfather lent money to father and told my father to take all the risk of the business as he will just be a accountent in business. So for business my father built a factory, a kitchen, two storage rooms and staff room from the money he got from my grandfather on my grandfather's land in Assam that he got from partition between his brothers. After a year of hard work my father succeed in business but because his father told him he called his brother (my 2nd oldest uncle) and took him in business. Then my uncle started working but after some time my grandfather said he, my father and uncle are three equal partners in business. After that my grandfather came back to Rajasthan and because my father trusts his brother so he gave accounts to uncle and my uncle with grandfather Started to steal money in lakhs from business. So after my mother went to Assam and checked the accounts she told my father and because of all this my father told uncle to pay and leave. But he didn't leave and called my grandfather to come back and make decision. My grandfather came and said that my has to give my uncle 10 lakh rupees then he will leave. He didn't even talk with my father and just gave his decision. But when we went there my oldest uncle even threatened my grandfather to hand over his all property but he did nothing. But when my father told him to give him his rightful place he refused. When my 2nd uncle left he said in future I never ever will set foot here and he left for Rajasthan. But even after all of this different from all his brothers my father sent medicines worth 25k and for expenses 5k every month. And now my grandfather sent my father a non judicial stamp in which he has written That in Assam all the house and 4 shops are left to oldest uncle, the business of my father and the factory, kitchen, both storage, staff room are left to second uncle,and on back 2000 sq. Ft left to my father and rest is for oldest uncle And in Rajasthan my 750 sq. Ft house he sold and rest house and land is for 2nd uncle. He is constantly torturing my father mentally and emotionally I don't know what to do and father because of business id very busy. My oldest uncle even threatened my father sometimes. I hope you can give me some useful advices so we can save homeand our business.