Ancestral property share or claim between two step brothers and sister

Our grand father died in the year 1993 with out making a will( intestate)and held Katha in his name during his death. From his first marriage ( he had one elder son ( now aged around 85 years- has to two sons and two daughters - now holds Katha in his name as kartha of joint family)and a daughter ( who was married and had one daughter of her own and both ( mother and daughter)died in the year 1966 and also her husband died after a year or so and they have nobody or heirs to claim anything since 1967) My grandfather's first wife died may be in the year 1944-45. And my grandfather father married again for the second time in the year 1945 ( to my grand mother ( she died in the year 1958)and had two children One elder daughter (- she has one son and one daughter ) and she too passed away in the year 2012( aged around 66 years) And the youngest son ( my father ) aged around 70 years.( Has two sons) My question is based on the above family tree Is the Ancestral property going to be divided into two parts/ share ( i.e children's of first wife and children of second wife) or Is it going to be divided into equal shares/ parts between the surving step brothers and the heirs ( one son and daughter of deseased daughter ) Will it be 3 ( three shares)then? Very confusing because as read in the internet ( what is the notion partition rules etc.? because my grandfather died in the year 1993 and his first wife in 1944 , and second wife in 1958 and my aunt in 2012 . Your answer to the question will help us to go for correct partition between step brothers and sister as per the law. Thanks in advance