(4)If after making of an order by the Assesing Officer under sub-section (1),—(a)a return of income is furnished by the assessee, under section 263 or in response to a notice under section 268; or(b)a regular assessment of the income is made in respect of a tax year, later than the assessment referred to in sub-section (1), the Assessing Officer may amend the order referred to in sub-section (1), and may require such assessee to pay advance tax on the specified sum, calculated in the manner laid down in section 405, on or before the due date of each instalment specified in section 408.
