Validity of a partition deed copy.

My father and brothers wrote a partition deed in 1996 (on stamps value of ₹10 and ₹170 in total) signed by witness but not registered. It was mentioned in the partition deed that a particular land shall belong to me and the same is added to my father & mother's joint account in the partition deed. I'm the only sister of my 2 brothers but not interested in equal share of the ancestral properties but just the property allocated to me in partition deed. Now since my father is no more and it was mentioned that my mother would enjoy the complete rights on the land allocated to me, can I change the title to my name with the support of mother and one brother. The other brother is opposing to it. I just have the photostat of the partition deed but one of my brothers, my mom and also the witness of partition deed support me. I've heard that the deeds made before 2005 are valid although they are unregistered. Thanks in advance for the advice. We are a Hindu family.