Every contract entered into by the Society, trust or body in relation to its undertakings for any service, sale or supply, and in force immediately before the appointed day, shall, on and from the expiry of one hundred and eighty days from that day, cease to have effect unless such contract is, before the expiry of the said period, ratified in writing by the Central Government or, as the case may be, the Foundation, and in ratifying such contract, the Central Government or, as the case may be, the Foundation may make such alterations or modifications therein as it may think fit:
     Provided that the Central Government or, as the case may be, the Foundation shall not omit to ratify a contract and shall not make any alteration or modification therein,--
         (a) unless it is satisfied that such contract is unduly onerous or has been entered into in bad faith or is detrimental to the interests of the Central Government or, as the case may be, the Foundation; and
         (b) except after giving the parties to the contract a reasonable opportunity of being heard and except after recording in writing its reasons for its refusal to ratify the contract or for making any alteration or modification therein.