Undisclosed income declared not to affect finality of completed assessments.

189. A declarant under this Scheme shall not be entitled, in respect of undisclosed income declared or any amount of tax and surcharge paid thereon, to re-open any assessment or reassessment made under the Income-tax Act or the Wealth-tax Act, 1957, or claim any set off or relief in any appeal, reference or other proceeding in relation to any such assessment or reassessment.