A co-operative housing society is facing a significant property tax demand from the BMC, dating back to 1995-96, with a hefty penalty. They are unable to provide proof of payment as bank records are unavailable and office documents are lost. Adding to the complexity, the audit report from that era lacks proper authentication. Now, the former secretary, who is the only living signatory, needs an NOC to sell her flat, but the society is hesitant due to the unresolved tax issue. The society is seeking advice on whether to issue the NOC, the necessity of indemnity bonds from both seller and purchaser, and how to proceed if the seller refuses.