Release deed requirements

Hello, I and my wife have filed for mutual divorce petition in court, as a part of mutual agreement we both have mutually agreed to release share in each other property. We have one jointly owned apartment (under construction), me being first owner and she is co-applicant. She has agreed to relinquish her right in that apartment in my favour and I will have to do a release / relinquish deed. Now the original agreement to sale which was done with builder on 20% payment is with bank from whom I took the loan and made my wife as co-applicant in home loan agreement too. questions to execute release deed between us, do we require original agreement which is with bank? ( Bank is not ready to release the agreement unless home loan amount is paid, which I don't have the entire money). is there any way by which I become sole legal owner of the apartment like by executing a MOU stating she is releasing her right in my favour? what is the stamp duty and registration amount to be paid? Experts please provide your best advice or any other option. Thanks & Regards.