Borrowers immovable property becomes npa

Hello Experts, What if a guarantor have given a collateral security to a bank which has become NPA and bank has auctioned the property which is non movable property. The successor bidder gave offer which bank has accepted it, if the same amount, if i offer to bank whether bank will accept or not...what is the RBI guidelines in this, appreciate your response here. Regards, Sohail Ahmed