How to get Divorce if one's partner refuses to give divorce in India?

I am a final year BTech student and currently interning at Bengaluru.I am of a Telugu family from Hyd.I am speaking on behalf of my mother also.We are facing domestic violence for the past almost 22 years from my father and his sister and are a middle class family.We had faced instances for example,like turning off the power in the flat,pouring water in the flat,taking my school bag away during my school days,on pressure made my mother sign on some bank documents by blackmailing not to give my school bag.We would like to break ties with him completely now as he has created a scene at my office also & is threatening me now that he'll badmouth me at my school,college & office;put false parent harassment case on me & false cases on both of us & has become unbearable.I would like to know on how we can proceed legally & know more about the process because he will not agree for a mutual divorce & we cant extend it for years long together as we are a middle class family and cant afford it