Possession of a legally owned flat

Dear Sir, I am the second wife of my husband. His first wife passed away leaving behind two children. We, me and my husband own two flats in our name, each financed by a bank. In one of our flats, my mother in law, along with the two children from first wife stay. Recently my brother in law also started to stay there. He is a recognised anti social element. Currently we are going through some financial strain. And hence we decided to vacate the flat and sell it off. It was meant to settle our liabilities with both the banks. But my mother in law and brother in law are refusing to vacate. I approached the City SP, who fortunately found a criminal case under investigation against my brother in law. And in course, he got arrested. Now my mother in law feels that I have instigated this arrest. And she is unwilling to vacate the flat. I am aware of the recourse to approach the court and file an ejectment suit, but that will be an endless process. It might take 2-4 years. The flat is registered in our name, we pay the IT return annually, and the flat is morgaged with the bank. We are not in the situation to pay the bank instalments. I fear that if we do not do something, the bank will enforce Sarfesi Act and take possession and sell my property as less than half the value (as this the amount that I borrowed 50% of the actual cost). Also, if I sell the flat to a strong buyer, there still be the issue of a delivery of possession. And if the buyer resorts to any otherwise means, it may get us involved into a criminal litigation. Kindly suggest me a recourse that will save me time, and will get my objective fulfilled.