1) once gift deed is made duly stamped and registered your father would be absolute owner of said house . your grand father could not make a will in respect of said house when he was no longer owner of said house
2) your grand father cannot bequeath 1200 square feet of land to your uncle which is owned by another person .
3) it does create suspicion about genuine ness of the will
4) ask your uncle for copy of the will .
5) if uncle refuses to do so you can obtain certified copy of will from sub regsitrar office .
6) check whether will has been signed by your grand father and attested by 2 witnesses
7)whether your grand father was of sound mind at time of execution of will .
8) you can issue legal notice and file suit for partition .
9) if your uncle relies upon will and applies for probate you can oppose grant of probate to your uncle . raise plea that will has been forged and fabricated