Gift Deed/Partition Deed

Dear Friends, Two brothers and a sister have been gifted a property vide gift deed by their father. The property is self-acquired by their father. All the three siblings are now co-owners. They want to construct residential units (3 floors) to be owned individually (each floor for one sibling) Bank is not comfortable to give loan on gift deed. They insist on a partition deed to be drafted between three siblings. a) Is it mandatory that loan can be give only on basis of partition deed? b) Why can't bank give loan on the basis of gift deed especially when the arrangement is crystal clear? (in the gift deed it is clearly mentioned that three siblings will own the property in equal proportion) c) Is it ok to enter into a partition deed? whether legally there will be any issues for the three siblings? d) Can we enter into a Memorandum of Understanding (MOU) instead of partition deed and will it have legal validity if it is not registered? Three siblings objective is to consturct three floors to be owned individually. Regards Ram