Will document

The rights of your father is a Trustee for others in possession and enjoyment and not independent for him alone.  All legal heirs have equal rights as stated in the will.  If your mother was having independent income of her own and if your father challenged the will in the past, there might have been some way to claim exclusive rights.  But, when a will is left unchallenged your father can not claim exclusive rights.  As your father is either enjoying benefits of rent or staying, paying muncipal taxes is not a big thing.  If you challenge, they can even demand for mesne benefits also, please remember.  Mutation in your father's name alone can not give you title, when there is a will giving equal shares.  (According to me even mutating in your father's name when the will is in four sons name is itself fraudulent).  A will not challenged within limitation period is a bonafide document.

Thanks for your reply.

As per original title , Both my grandfather and grandmother has equal rights , so still my grandfather can write will for whole settlement?. As my father is only son of title owner (grandmother) , he can get any rights?