(1B)(a)In a case where an assessment under sub-section (3) of section 15 or sub-section (1) of this section has been made for the relevant assessment year, no notice shall be issued under sub-section (1) by an Assessing Officer, who is below the rank of Assistant Commissioner, unless the Deputy Commissioner is satisfied on the reasons recorded by such Assessing Officer that it is a fit case for the issue of such notice:Provided that, after the expiry of four years from the end of the relevant assessment year, no such notice shall be issued unless the Chief Commissioner or Commissioner is satisfied, on the reasons recorded by the Assessing Officer aforesaid, that it is a fit case for the issue of such notice.(b)In a case other man a case falling under clause (a), no notice shall be issued under sub-section (1) by an Assessing Officer, who is below the rank of Deputy Commissioner, after the expiry of four years from the end of the relevant assessment year, unless the Deputy Commissioner is satisfied, on the reasons recorded by such Assessing Officer, that it is a fit case for the issue of such notice.
