55. Orders constituting Appellate Tribunal to be final and not to invalidate its proceedings.–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].
Section 55 IT Act — Orders constituting Appellate Tribunal to be final and not to invalidate its proceedings
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