Loan in co operative bank

Mortgage Loan of Rs. 25 lacs availed on 2006, it was not used till Mar.2007 and additional loan of rs. 10,45,000/- was released, as on April 2008 balance in the ML account was 3550000/-, the same was availed by husband by pledging flat in his wife name. And the same was debited to current account of husband business account. On 4/2008 interest was debited 290000/- from the bank in husband's current account. Later not paid any interest nor they debited to the said current account. In the year 2011, 2015 and 2017 action was taken for auctioning the property pledged, but no buyer came forward to buy the flat as it is car parking area which was constructed in balance left over area of car parking in stilt floor. Now they are trying to sell for lesser rate 25 lacs, to sell they are asking some parent documents from us, and we came to know that they are filing suit for recovery of balance amount. my question is whether they can file suit, what is the time limit for them, as read above questions, I noticed it is 12 years, at last they are asking us to pay balance 10-12 lacs to the bank. Borrower is not remembering signing the papers for availing the loan and it is not credited to her account directly. waiting for your favourable reply. please guide how to proceed.