Lost original documents

The property belongs to your father who passed away.  So your mother and the children of your father have equal rights over the property.  For your brother's share, his wife and children have equal rights over the share of your brother. So file a partition suit if any dispute is there.  Otherwise, amicably settle the issue.

After your parents demise all three sons  got equal share as successors  that is 1/3rd share equal ,  your un married   brothers 1/3 Rd share is inherited by you if your elder brother is pre deceased and his widow or his  childrens  cannot claim any share ,so you inherit 1/3+1/3= 2/3 Rd share  .try to solve peacefully .

Thank you Sir. But how do i get the documents as the origunals are not traceble ?

If it is registered in sub registrar office then try to obtain certified copy and assessment statement from  concerned authorities ,light bill ,water tax paid bill etc  , with relevant documents you can file declaratory suit .