Right of Married Daughter's son in Father's ancestral property

We live in old house jointly owned by my late grand father and his real brothers. As on date legal successor entry is not made and house is still in the name of my Grand father as per City Survey record. My grand father has passed away in 1971. My father and my father's married sister also both expired in 2015. Now my father's sister's son and husband means (in gujarati Faiba no son and Fuva mean's husband) are asking for share in old house, which we are residing although are having their house, shop etc. I have read somewhere that married daughter's cannot claim right in property of father if father has passed away before 2005 as per Hindu Succession Act. My grand father had not made any will. In light of above, please guide me.