Undisclosed income declaration bars reopening of completed assessments and set-off after scheme payments. A declarant who declares undisclosed income and pays the applicable tax and surcharge under the Income Declaration Scheme shall not be entitled to re-open any assessment or reassessment made under the Income-tax Act or the Wealth-tax Act, nor to claim any set-off or relief in any appeal, reference or other proceeding in relation to such assessment or reassessment.