Betrayal by Father

Dear Sir, Below is my situation. Appreciate any info if there is any possibility that I can get any relief through legal process: My father married third time after my mothers death. We are 5 brothers. My eldest brother is from my fathers first marriage and youngest from third marriage. My father was lecturer in 10+2 college and retired 7-8 years back. I started working as engg from 2008. Since then I started sending all my savings to my father.(clearly evident from bank account statment) My father used money to build 3 storey house. All is rented now. Now my step mother brainwashed my father.He has turned greedy. Now he says house belogs to him. But he did give one plot through gift deed and says he's done with me. If I invested money for my own sake instead of giving it father, I would have bought 5 such plots myself. I just took the plot and stopped talking to my father and it was so unbearable to me how my father betrayed me. While I was not talking to my father, they tortured abused my brother saying they can't feed him anymore. My brother is having Rheamatoid arthritis, he can not work. I took him to me after I came to know about this. My hard earned money is gone and I am taking care of my brother. My father is enjoying rent+pension~50k. What help can I get legally under these circumstances?