Possession notice issued

Hello, My father took a loan from PNBHFL (PNB Housing Finance Limited). Loan details are mentioned below: Loan Account Number: [deleted] Sanction date: 30 May 2009 Sanction amount: Rs. 15,09,480 Total amount paid: Rs. 23,33,347 Amount remaining as per Bank: Rs. 12,10,030.57 Loan is under NPA and a notice was sent to my address on 20 September 2018, against which an application was submitted in the bank mentioning the current financial crisis and an OTS (One Time Settlement) was offered. Amount offered was Rs. 4,00,000. We didn’t get any response from the bank since than and on 04 February 2019, a possession notice (For immovable property as per Rule 8(1) and Appendix-1V) was issued by the bank and was pasted on the wall of the main enterance. What am I suppose to do here? My father is an Ex-Army relying on pension. His pension is Rs. 22000 and he has 2 loans (one against pension with monthly instalment of Rs. 7,555 and one against property from PNBHFL with monthly instalment of Rs. 21,000). Please suggest. Thanks