Section 17(4BB)(b) in The Reserve Bank of India Act, 1934
(b)repayable on the expiry of fixed periods not exceeding eighteen months from the date of such loan or advance, against securities of the Central Government or of any State Government, of any maturity, or against bonds and debentures issued by that financial institution and guaranteed by the Central Government or any State Government, and maturing within a period not exceeding eighteen months from the date of such loan or advance: