Divorce due to mental harassment

Dear Sir/Madam, My mother is suffering in her marriage and due to lack of money, we never had the courage to file a divorce case. My father is harassing my mother since my childhood and he continued this till now. We filed a case against him in National commission Women and had withdraw it later. Police issued his warning letter under section 398A but he is not stopping. He hardly gives 8k from his 39k pension and nothing else for saving for my marriage or medical expenses. We cannot take this any further so please let me know how to go about divorce and can my mother get house and his pension every month. Ps:- My mother is illterate and cannot earn on her own. She is dependent on father for her expenses.