Rights of Second Wife and her daughter

Hello, My father-in-law has expired a few weeks ago and he was married to two women. Father-in-law: # Did not write any will for the properties # His bank accounts nominee is first wife's three children # His nominee for the pension is second wife First wife: # He had married his first wife in 1990 and they had three children. # All the earned properties (land, house, etc..) were equallly divided and registered to both of them # Both of them started living separately since 2012 # First wife died in 2018 # Death certificate was prepared with my father-in law's name as husband's name. # The legal heir of the first wife's property was made in the name of my father-in-law and his three kids from the first wife. Second wife: # He had married his second wife in 2015 and his second wife had one kid who was not born from my father-in-law # Second wife and the kid who was not born from my father in law have prepared the death certificate of my father-in-law with Spouse's name as second wi