Section 126 of the Transfer of Property provides for conditions where a gift may be revoked.the following are those conditions-
(1) That the donor and donee must have agreed that the gift shall be suspended or revoked on the happening of a specified event;
(2) such event must be one which does not depend upon the donor's will;
(3) the donor and donee must have agreed to the condition at the time of accepting the gift; and
(4) the condition should not be illegal, or immoral and should not be repugnant to the estate created under the gift. Section 126 is controlled by sec. 10. As such, a clause in the gift deed totally prohibiting alienation is void in view of the provisions contained in sec. 10. A gift, which was not based on fraud, undue influence or misrepresentation nor was an onerous one, cannot be cancelled unilaterally.
Such a gift deed can be cancelled only by resorting to legal remedy in a competent court of law.
Further please be aware that though your father funded fully for the purchase of the said property, it was purchased on your mother's name, so it becomes her own property.As per MWP Act, 1874, whereas by force of the said Act all women to whose marriages it applies are absolute owners of all property vested in, or acquired by them by any mode or manner it shall become her own property.