The rate of interest payable by the promoters to the allottees or by the allottees to the promoters, as the case may be, shall be the State Bank of India highest Marginal Cost of Lending Rate plus two percent: Provided that in case the State Bank of India Marginal Cost of Lending Rate is not in use it would be replaced by such benchmark lending rates which the State Bank of India may fix from time to time for lending to the general public.