So my Questions are following assuming Mutation will happen:
1> Is this document is equal to what we say is "Registry of a Property" or It is a "Gift Deed" or is it a "Sale Deed" or is it a "GPA" if none what is it ?
This is none of the ones what you have mentioned.
This is not a vehicle that you signed a TO form.
This transfer what you have executed is invalid in law until the same is registered.
Further there is no blood relationship between married sisters or between husband and wife.
Even then the registration of the transfer deed is essential.
2> If this is not Registry, that one option we go for registry other is not, answer as per below options
A> If we chose to go for Registry than will Stamp Duty occurs as stamp duty is waived off as per link shared by me.
It is your misconception about it, hence you may clarify the same from the local sub-registrar
.
B> If we dont chose to go for registry will it be a problem in sale of this land or anyone can encroach this or my sister can claim this as her property.
Without registration of the deed, you cannot acquire clear and marketable title to the property hence you may not be able sell it.