Getting possession of property or my bid amount from bank

I had purchased a property from bank in 2011 but till date I have not got the physical possession of the same. Though 2 attempts have been made by bank in 2012 and 2015 to vacate the property by the help of police but somehow police could not vacate the same and hence I have not got the physical possession. I had purchased the property and I was single bidder though it was 3rd auction notice in which I bought the property. The previous 2 auction notice could not turn up any bidder. When I had purchased one more bidder was there but he was disqualified as he had deposited a cheque instead of DD. I have got the sale letter from bank in 2011 but still registration has been pending as I had planned to get the property registered only after getting physical property. DRT had given chance to pay the debt to original holder of property but he was not able to pay the debt. DRT had given chance on 2 times. Now the owner of property had moved to high court and filed a writ to get the sale invalid. What should now I do? Can I ask bank to repay my payment made ? How much can I claim for that and how much interest will I get on my payment made to the bank.I had made 725000 to purchased the property. Can bank move again to DM to get the possession or we had to wait for writ decision. Thanks