Is gift deed better or release deed or any other affidavit will work to transfer property?

The scenario in my case is, the new property my parents got did booking and registration for, the builder told us we have time till we get possession around 2025, and that's why my father invested the money we reserved to pay. Now we are going for home loan for which I am eligible, however my name is not involved in that property, thus they are asking us to pay for the registration and stamp duty again. None of this was cleared before going through process, also I have one younger sister who is ready to sign NOC. We are asked to do gift deed but again that will cost us stamp duty amount, which we are not willing to pay, and now we are confused. My questions are : - will simple Affidavit or agreement, along with my sister's NOC will work mentioning my involvement in property? as most of the payments was done through me, however I am not part in registration of the property -Will gift deed or release deed will be better to deal with this? How much stamp duty for both will be charged? - Is there any other way that I will have to pay minimum charges for home loan reasons , as my involvement is necessary while disbursement?