Section 55
. Orders constituting Appellate Tribunal to be final and not to invalidate its proceedings . –N –No order of the Central Government appointing any person as the 1 [Chairperson or the Member] of a 2 [Appellate Tribunal] shall be called in question in any manner and no act or proceeding before a 2 [Appellate Tribunal] shall be called in question in any manner on the ground merely of any defect in the constitution of a 2 [Appellate Tribunal] .