what is national saving certificates? why is it not included while measuring money supply?

National saving Certificates (popularly known as NSC's) are one of the source of investment for small savers. It carries high rate of interest of 8.5% per annum. It is specially designed investment scheme for the income tax assesses whereby they get deduction under Section 80C of Income Tax Act, 1961. The maximum deduction permissible is Rs 1,00,000 but there is no such limit for investment, an investor can invest any amount as much as he wants.