Not to able execute Gift Deed

My father has an self earned property. He has 1 son(myself) and 2 daughter(both got married). My father and mother stays with me and I take care of their food, shelter, day to day expenses, all medical needs, property maintenance, paying property taxes etc. Father is ill and his health is getting deteriorated day by day. He wants to pass on his property to me and ready to execute gift deed. But many years ago for business reason he mortgaged the property with some private financial institute and law suit was filed against my father for some disconnect with both the parties. In the mean time financier ran away with public money and didn't appear for court proceedings and the case was dismissed in favor of my father. Its been more than 15 years now and we are not able trace the person to collect our property document. Having said that when we approached the sub-registrator office for gift deed, they are looking for the original document to be verified. We are in a situation not able to trace the financier and not able to execute the gift deed. We want to get the gift deed done as soon as possible before my father health become even more worst, because after his life we see chances of my sisters claiming the property share.