Hi
1) Since B1, B2 and B3 got the property of A1 through a WILL, the property obtained by B1, B2 and B3 are self acquired properties(absolute property) and not ancestral in nature.
2) Also, B2 has done settlement to the legal heirs of B3 and hence the property obtained by B2 from B3 will also be absolute property of B2.
3) Hence Succession will be in accordance to Section 8 of Hindu succession act and in accordance to Class I of schedule.
4) Please note Section 6 of Hindu Succession act is applicable only in case of Undivided properties which are ancestral in nature.
5) The property changes the character once if any partition/ will/gift/settlement is executed by any one of the ancestors and acquires the character of self acquired / Absolute properties.
6) So, on the date of death of B2 (i.e in 1967), his legal heirs namely
a) wife c2.1,
b) 1st son c2.2,
c) 2nd son c2.3,
d) and daughter c2.4
7) The legal position as of today (on account of death of legal heirs would be)
i. D2.2.1 -MALE
ii. D2.2.2 -MALE
iii. C2.3- MALE- ALIVE NOW
iv.. FEMALE HEIR D 2.4.1
8) Please note, if there is a death of family member, his legal heirs will succeed to the property .
9) Technically, the property will vest in three shares and each one of them namely C2.2, C.2.3 and c2.4 will be entitled to 1/3rd share .
10) So, technically,
a) C2.2 will get 1/3rd share and his children D.2.2.1 and D.2.2.2. will get equal share out of 1/3 share allotted to C2.2.
b) C2.3 will get 1/3rd share
c) C2.4 will get 1/3rd share and her daughter D2.4.1 will succeed to this share in full
Hope this information is useful.