27 February 2010
The following has been added in respect to remuneration: The following items shall be substituted for the existing items (1) and (2) of sub-clause (v) of clause (b) of section 40 by the Finance (No. 2) Act, 2009, w.e.f. 1-4-2010 (i . e. from A. Y. 2010 - 11)
So it is w. e. f. 01.04.2009. However the amendment also required amendments in the partnership deed and any changes in the partnership deed cannot be made retrospectively