Stamp duty on gift deed in mumbai

There is no Tax implications. Since, I am not aware of property value which you want to gift, you will have to calculate by youself. 

.[Provided that, if the property is gifted to a family member being the husband, wife, brother or sister of the donor, then the amount of duty chargeable shall be at the same rate as specified in this article or at the rate of rupees ten for every rupees five hundred or part thereof on the market value of the property which is the subject matter property which is the subject matter of the gift, whichever is less.]

This is provision for calculation of stamp duty on gift deed as per Bombay Stamp Act. See bold and underline sentence and calculate accordingly. 

The stamp duty generally vary in case of GIFT from 2% to 5% depending on state to state. As such there is no tax complications.