How to determine shares in family property

WE ARE 2 BROTHERS BY BLOOD BUT NOT ON PAPER. My father handed over me to my childless uncle ( this uncle is not brother of my father by blood). Now after their(uncle) death all property transferred in my name based on documents. my brother now refused to share any property of my father (by blood) as there is no documentation available. He captured the house of my uncle located in ballia (native town). He threatened that if I raise any claim for my blood father property. Then I need share from your(cousin uncle) property. Please advise me for further course of action. Please note I am not adopted by my cousion uncle, They take care as guardian and use their name as father in all my certificates.