Rebate of income-tax reduces computed tax using specified deductions, subject to an aggregate cap not exceeding pre-deduction tax liability. Rebate of income-tax allows specified deductions to be set off against the income-tax computed on an assessee's total income, applied to the tax amount as computed before chapter deductions. The aggregate of such rebate deductions is capped and cannot exceed the income-tax computed before allowing the deductions under the chapter.