Living separately and not willing to give Mutual Divorce

My Father and Mother are living separately. My father is kind of psychotic who tortures by words, he is two-faced. He speaks something non-sense and the next day he denies that he spoke that. My father had been doubting the morality of my Mother and asked her to get out of his house. My mom and me left the house and we are living on our own with my earnings. We left our house in 2013 and it is now 2017. Immediately in the mid of Oct/Nov 2013 he gave my mom a cheque for 3L and he got married in Nov 2014 If we asked him about his marriage, he says that she is only maid servant of house We are living on our own since 2013 without his intervention. He had never even tried talking with us meanwhile. We need to have all the documents like aadhaar, ration card to be updated with our new addresses for which I need legal documents for my mother to be submitted. I am afraid that he wont even be ready for mutual divorce because he wants to torture us by not to give divorce. My Mother doesn't want to live with him and we want Divorce or Separation legally. PS: He said to my Mother that If we apply for divorce he would tell in court that he wants to live with us, but if we go home he would torture us by any means. Can someone let me know the solution ?