Indian succession act

One christian lady Doctor lived as spinster during 1920-1998 and earned immovable properties. Her name is Mary and her father name is Joseph. So, her name is Mary Joseph. She had 3 brothers and 3 sisters. She executed a registered will bequeathing her A and B immovable properties to her brothers and sisters. 'A' property to all her brothers and sisters, but 'B' property only to her youngest sister who take care all her life time. later she died. As per will her younger sister succeeded 'B' property and died intestate 2007 leaving behind her, her husband, one daughter and one son as her legal heirs. Her husband also died intestate 2012 leaving behind his unmarried daughter and son as his legal heirs. later his daughter died on 2015 as un-married and son also died on 2018 as un-married. Now the question is....who are the right persons to claim the property? deceased husband brothers and their children have rights? or deceased original beneficiary's brothers and sisters children entitled? Or both father side legal heirs (his brothers and sisters children) and mother's brothers and sisters children entitled share as per indian succession act? Pl give me clarification,....thanQ sirs