Mhada flat to sell after 5years

I have a mhada flat in mumbai which has completed 5yrs and looking to sell my flat to a buyer. His funding is maximum loan from bank (95%). I have intimated mhada my intimation to sell my flat to a buyer and upon receipt will do stamp duty. Buyer’s bank is asking for NOC (post stamp duty and reg) for transfer (new owner) and mortgage (bank) from mhada as compulsory documents in order to disburse funds to me. Alternatively bank is fine to disburse me as long as new buyer sends acknowledged receipt from mhada on the NOC (transfer and mortgage). Bank will be marking a lien on buyer’s bank account untill the two NOCs are submitted by buyer in case of second option above. I have asked the buyer to include default clause stating in case of non payment of full amount within 45 days the transaction will be deemed cancelled and xx amount will be deducted from token amount however their lawyer has asked to refrain using such clause in the agreement. From a seller’s (me) point of view key things to keep in mind in terms of conditions to be included in the sale agreement.