Questions about what a divorce entails for my mother.

Hello, my parents have been going through some marital problems from quite some time and separation or divorce seems the only way. Before we approach a lawyer in real life, I would like to know what should we expect that is going to happen. Background: Parents are married from the past 25 years. Father has been physically, mentally & verbally abusive in the past and continues to be one till date. I don't want to go in details but he is a narcissistic with an absolute zero chance of changing himself. Question 1- Would my mother need to pay alimony to my father? This question might seem stupid, but hear me out. My mother is a government employee and her monthly income is significantly more than my father who is a deadbeat and refuses to pay a single penny for house expenses. He has been unemployed from quite some time now and receives rent from properties he owns whenever it's occupied. Question 2- What would happen to the assets primarily the current residence? The house was bought by my father and has his name on the deed. We have been living in the house for close to 15 years now and my mother has paid for all the renovation expenses to the property and the furniture as well. This sums up to a significant amount as well. Would the spouse have any right on the property despite not having her name on the title deed ? Question 3- Other properties Apart from our current house, my father has other properties in our city as well. Half of those properties were paid by my mother. She was coerced into paying for it and does not have her name on the title deed as well. I asked whether she had any proof and she said no, but I think maybe the bank can help with it ? This was over 15-20 years ago so I'm not sure about this. Either way, is there any way that she can get what is hers? I have a sister who is also mentally exhausted of the arguments and the abuse and supports our mother with the decision. She is over the age of 18, so am I. We live in Delhi if it makes a difference. Thank You!