Land partitioning dispute.

My Grand-Father had 4 Sons (A,B,C,D) and 3 daughters, after his death the elder son (A) had the land papers with him, now the elder son (A) has 2 sons 1 daughter viz a1, a2, a3, another elder son (B) is having 3 sons 1 daughter viz b1,b2,b3,b4. third elder son (C) is having 1 son & 1 daughter viz c1, c2 and the remaining son (D) is having 1 son viz d1, now partition dispute is person A & B are dead. technically only 4 shares of the land to be partitioned. but now the elder son of A (who is having the papers) is stating the land should be partitioned among total 10 people viz (a1, a2, a3, b1, b2, b3, b4, c1, c2, d1) My Question, is there any law/rule. that the land should be partitioned in 4 shares not with 10 shares.