We have a property in my deceased father's name. Mother is also expired. Recently lost my elder brot

We have a property in my deceased father's name. Mother is also expired. Recently lost my elder brother also. I have one younger brother. Both of us have our families and living in our father's property. No will was made either by my father or mother. Property was self acquired by my father. My SIL is claiming a part in the property now. What does Christian/India law say about a Christian widow getting a share in FIL's property?