2Provided. that where any agreement has been reached between the Commissioners and the Corporation of Calcutta providing that the annual value of the properties vested in the Commissioners is to be ascertained for the purposes of municipal assessment on a basis different from that set out in the foregoing provisions of this section, the annual value may, with the approval of the State Government, be ascertained on such basis with effect from such date (which shall not be earlier than the 1st day of April, 1952) as the State Government may direct.
