Brother put false info in succession deed please advise

I relinquished my rights some years back to my brother to property which was belonging to my dad as that what I was told, but later I found out that all property was in my grandmother name and there was a Will which was made by my grandmother in my name n my brothers. My brother has falsely done the deed of succession with false information on it?? Can I revoke my right and how can I get my share that is mentioned in the will back?? I don't have access to the will as I live abroad....