Alienation by the Karta without legal necessity or the benefit of the estate is:

A manager’s unauthorised alienation of joint Hindu family property is ordinarily voidable at the affected coparcener’s instance, rather than void from the outset. Raghubanchmani expressly distinguishes voidable from void even in the absence of legal necessity. An alienee does not obtain an avoidance right merely because the manager exceeded family powers; binding consent or other recognised justification is a separate issue.