Provided that in a case—
(a) where a return has been furnished during the period commencing on the 1st day of October, 1991 and ending on the 30th day of September, 2005 in response to a notice served under this section, and
(b) subsequently a notice has been served under sub-section (2) of section 143 after the expiry of twelve months specified in the proviso to sub-section (2) of section 143, as it stood immediately before the amendment of said sub-section by the Finance Act, 2002 (20 of 2002) but before the expiry of the time limit for making the assessment, re-assessment or recomputation as specified in sub-section (2) of section 153, every such notice referred to in this clause shall be deemed to be a valid notice:
Provided further that in a case—
(a) where a return has been furnished during the period commencing on the 1st day of October, 1991 and ending on the 30th day of September, 2005, in response to a notice served under this section, and
(b) subsequently a notice has been served under clause (ii) of sub-section (2) of section 143 after the expiry of twelve months specified in the proviso to clause (ii) of sub-section (2) of section 143, but before the expiry of the time limit for making the assessment, reassessment or recomputation as specified in sub-section (2) of section 153, every such notice referred to in this clause shall be deemed to be a valid notice.
Explanation.—For the removal of doubts, it is hereby declared that nothing contained in the first proviso or the second proviso shall apply to any return which has been furnished on or after the 1st day of October, 2005 in response to a notice served under this section.
(2) The Assessing Officer shall, before issuing any notice under this section, record his reasons for doing so.