Whether a gift of immovable property has to be made only by the donor or his authorised representative can also make a gift?

Section 123 of ‘Transfer of Property Act, 1882’ defines the mode of making a gift.  It prescribes that the gift should be made by a registered document signed by the donor or on behalf of the donor, attested by at least by two witnesses.  So any authorised representative of the donor may also make a gift.  But authorisation, which is the power of attorney, given to the representative should be clear as to the provision for making a gift.  The power of attorney should be properly stamped.