Tax exemption extension under section 10(23FE) prolongs the operative period by government notification, with transitional saving. The Central Government, under sub-clause (iv) of clause (c) of Explanation 1 to clause (23FE) of section 10, amends the principal notification of 2021 by substituting the previously specified terminal date with a later terminal date to extend the period of the tax exemption; the amendment preserves an express provision concerning acts or omissions from 1st April, 2025 until the date of publication and is effected by Notification No. 77/2025 dated 11th July 2025.