How to check Auction Property.

Thanks in advance for your advice. I am considering a property- which is being auctioned by Kotak bank. The owner took loan from Citi financial in 2007. Citi financial sold the mortgage to Kotak. Now kotak is using SARAFRASI law and opening an auction. The property is in possession with Kotak - we can see the locks and notices on empty house. After checking with Kotak - the officer claims he has only 3 docs (which we have seen only xerox). A) original sale deed of current owner from previous owner in 1999. B) original sale deed of previous transactions in 1998. C) original current owner NOC from LIC Home finance in 2007- which he submitted in order to get loan from citi in 2007. Now my question is: A) How do I verify that the property is not mortgaged to some other lender? Bank or anyone else. B) How do we know if the owner has sold the property to someone else after 2007? C) How do i get and check the Encumbrance Certificate? D) what else shall I consider as risk in this property and perhaps avoid this deal with Kotak. Kindly advice your opinion. Thanks