UCO Bank would become the first Indian bank to raise funds via hybrid instruments after the Reserve Bank of India (RBI) issued norms for raising funds by issuing such papers.Crisil has assigned a rating of AA (Stable) to the proposed Rs 500 crore issue of hybrid instruments by the bank in two tranches - Rs 200 crore via Tier-I perpetual debt issue and Rs 300 crore via upper tier-II bonds.Roopa Kudva, executive director and chief rating officer of Crisil, said: "The ratings assigned to UCO Bank's hybrid capital instruments is a milestone in the evolution of Indian financial markets."