Financial torture by father

Dear, My name is Rahul and I am currently living in Hyderabad. My father is a central government employee. My father and his family members are bad people who have always tortured me, my sister and my mother. This torture was too much when I was living in Rajasthan. But in 2007 my father got transferred to Hyderabad. But the fighting between my father and mother continued in Hyderabad even though my father's family were not with us. However my father's family visited us in Hyderabad a few times and the series of torture continued. But I somehow managed to get admission into undergraduate course which will get completed in 2021. I did not take any legal action in these years because I didn't have any money. My mother and her family members also did not help. So I, my sister and my mother decided to somehow complete me and my sister's studies and waited all these years. But now the problem that I have is that I have come to know the future planning of my father and his family. My father is planning to settle down in Rajasthan after his retirement which will happen in 2026. We three kept telling him to buy a house in hyderabad(which he could easily buy). But 2019 has come and he didn't. We are still living in government quarter. My mother doesn't have any access to my father's money. We three don't even know how much salary my father receives. He just buys us food and things we need. We three don't want to go back to Rajasthan and want to live in Hyderabad. What to do?