Section 6(2)(b) in The Banking Companies (Acquisition And Transfer Of Undertakings) Act, 1970
(b)in saleable or otherwise transferable promissory notes or stock certificates of the Central Government issued and repayable at par, and maturing at the end of-(i)ten years from the commencement of this Act and carrying interest from such commencement at the rate of four and a half per cent. per annum, or(ii)thirty years from the commencement of this Act and carrying interest from such commencement at the rate of five and a half per cent, per annum, or