Dear Ramesh garu, Namastae. Before a specific and proper advice can be given, you should make it clear , if the property proposed to be given to your sister is ancestral joint family asset or self acquired property of any one of the donors in the family and also composition of the family that is, who would be the donors.
If the property is self acquired property the donor/s should necessarily execute and register a gift deed. It matters little whether it is towards pasupu kumkuma or otherwise, registered gift deed is mandatory.
If by chance what is proposed to be given is part of ancestral joint family family property, you shoould make clear whether yoou propose to give it to your sister towards her share in the coparcenary property or something in addition to her share. Because if there was NO earlier partition of coparcenary properties amongst male members in the family covered by registered partition deed or decree of court, your sister may now claim a share equal to that other male coparceners in her own right and again take something given to her as a gift from the family.. So let there be a definiteness in the matter amongst all the family members. And once it is decided the best thing is to go for a registered partition deed specifiying the proeprty proposed to be given to your sister is her share in the family assets following the family customary practice. In such an event all the family members entitled for partition shall join in the execution of the deed. The stamp duty payable on such document is 1% on the value of the small shares separated from the largest share.