Gift deed being nullified.

A Will was made some years back stating that the immovable property is to be bequeathed to charity and after those years later the same property was transferred in the form of a gift deed by the old mother M ( age 91) to her son B keeping siblings C,D, and E uninformed about such transfer. However, one of the siblings D is aware about the Will and possesses a copy of the Will. Can the Will overpower and succeed the Gift Deed? In other words can the Gift Deed be nullified?