The correct option is 2 (16 March 1949).

The Banking Regulation Act, 1949 came into force on 16 March 1949. This Act was enacted to regulate the banking system in India and to ensure the stability and growth of the financial sector. It provides a legal framework for the functioning of banks in India, including the regulation of banking practices, licensing of banks, and governance of banking companies. The Act plays a crucial role in maintaining financial discipline and protecting the interests of depositors and stakeholders in the banking sector.