Failure of one branch of the family to question the validity of an alienation in a suit:

The right of a coparcener or branch to challenge an improper alienation of joint family property is its own, so one branch's failure to sue "Would not bar the right of the other branch".

Only a decree binding on the other branch, for instance one in a representative suit covered by Explanation VI to section 11 CPC, or limitation running against that branch, could bar it.