The correct answer is RBI.

• Reserve Bank of India (RBI) is India's central bank, which is responsible for issuing and distributing the Indian rupee and controlling the Indian banking system.
• It also operates the key payment networks of the nation and works to facilitate its economic growth. 
• RBI began its operations on 1 April 1935 in compliance with the Reserve Bank of India Act, 1934.
• The RBI was nationalized on 1 January 1949 following India's independence on 15 August 1947.

• A credit rating agency (CRA, also referred to as a rating service) is a corporation that issues credit ratings that rate the ability of a debtor to pay back loans by making regular payments of principal and interest and the risk of default.
• Credit Review & Research Ltd (CARE) which started operations in 1993, is one of India's leading credit rating firm which offers multiple credit scores that help businesses raise money for their diverse needs and help investors make educated investment decisions based on credit risk and their own perceptions of risk-return.
• ICRA is one of the most experienced credit rating companies in India which rates rupee-denominated loan instruments offered by manufacturing undertakings, commercial banks, non-banking undertakings, public sector undertakings, municipalities and financial institutions.
• CRISIL Ltd is a global analytical firm offering ratings research and risk and strategy advisory services, and also provides the world's largest banks and major companies with high-end research.