Gift deed

Dear All, I have few queries and would appreciate your advice on the same. I reside in Mumbai with my parents. My father has a flat in Nagpur which he would like to sell off in future. The flat is registered in his name but the city survey and NIT mutation is pending. He is old and health wise also, it would be difficult for him to travel often for the registration and other legalities in case of selling. And hence, he wishes to give me the authority to do the needful on his behalf. Could you suggest the best option: 1) Gift Deed - If I go ahead with gift deed, then do I have to get it registered in Nagpur or can I do it in Mumbai? Also, would I have to get the property transferred in my name from NIT, NMC etc.? The registration fee applicable is on the value of the property, am I correct? After the gift deed registration, if I think of selling the flat, do my father have to come for any formalities (signing etc.)? Any other information that you can guide me with which I might be missing? 2) Power of Attorney - How about this? My guess is this will be valid for only a certain period of time. Please help me with the information. Many thanks.