property+divorce issue

My parents have been living separately for 7 years. My father wants divorce but mother does not. Primary reason for this is that mother indulged in infidelity 7 years back and my younger sister who was then 12 years old has caught mother redhanded. And my father has audio recordings in which mother has apparently accepted it. Apart from that my mother is a patient of schizophrenia since 1992 and till now her case has worsened. She now lives with her sister and is working as a teacher. Problem is that my father bought 2 properties in his life and both are joint in name of my father and mother, in which mother doesnot have a contribution of single penny. Though my father only put in all his hard earned money and effort but only because it is joint he is not able to build a home there. During these 7 years, both children me and my sister have been with papa and all our expenses and responsibilities have been taken up by father with absolutely no concern or help or contribution from mother. Entire fees, expenditure, my marriage everything was handled by my father alone.And during these 7 years my mother has filed several false cases against my father that he has left her for some other woman, he beats her, asks for dowry etc in mahila aayog and has even called police to our home once, sent police to papa's work place several times, but everytime authorities investigated and found my father innocent and realised that my mother is mentally ill. What can be done in this case, as after all this drama and trauma, my father doesnot want to live with her and wants both his properties back as he is bearing all our expenditures. Pls help. And also pls advice on how long could it take to get to end solution and approximate expenditure involved.