Domestic abuse from father and his first wife

Hello, My mother and me are constant vicitms of domestic voilence by my father and his 1st mother is second wife of my father and he married my mother because he was not having children from his 1st wife. From 23years,my father and step mother always verbally abuse my mother and me for no reason also both of them hits us and give bad words to us and in fro t of our relatives they show they are behaving good with mother had filed complaint to local police station but none of them helped us because they were given bribe by my father. Also my mother is now 60 yrs of age and not working and now I am going to pursue higher studies in other state,so I am in fear what will happen to my mother? She might get killed or mental by them and if my mother thinks of leaving that house with me,my father will falsely vla about she running away from home for her own selfish.please help me sir. I am in great dilemma, I dont have money to fight for my mother nor I can approach police cause eventually they will close case once they recieve bribe. Also let me know how to cla restraining order and if local police given bribe,will they drop or claim false claim on us? How long it takes to claim restraining order?if restraing order is applied ,will my father able to remove that order by any means?