1:-My husband is mentally disabled then how is it possible that he can arrange accommodation & other expenses.
Then if he is living in that house, you can rightfully occupy that house since that is your matrimonial home.
2:-My father in law have legal right that forcefully vacate that house if I am living since a long time in same situations.
You can lodge a criminal complaint against him for tortures and mental as well physical cruelties.
3:- I want to know if my father in law can't give share in property to my husband in that case what can I do for my survival.
You cannot claim a share in your father in law's property as a right.
4:- My husband is mentally disabled he can't understand these family matters(good or bad) can I claim anything on behalf of my husband he is not able to do anything like that.
You can remain in that house where he is living and seek the help of mediators to solve the current crisis, because legally you may not get any proper support or help.
5:- I only want to live in my Father in law house as I am living since for a long period but after the mutual divorce application he is not agree for that.
Then you go and start living in that house once again.
6:-What the court decided if I dis agree to give divorce by mutual. After that where I live what the court decide.
If the court dismisses his divorce case then you may live in his house as a legally married wife to him