Section 17(2)(bb) in The Reserve Bank of India Act, 1934
(bb)the purchase, sale and rediscount of bills of exchange and promissory notes drawn and payable in India and bearing two or more good signatures, one of which shall be that of a State co-operative bank or a State financial corporation or any financial institution, which is predominantly engaged in the acceptance or discounting of bills of exchange and promissory notes and which is approved by the Bank in this behalf, and drawn or issued for the purpose of financing the production or marketing activities of cottage and small scale industries approved by the Bank and maturing within twelve months from the date of such purchase or rediscount, exclusive of days of grace, provided that the payment of the principal and interest of such bills of exchange or promissory notes is fully guaranteed by the State Government;