(1) The general superintendence, direction and management of the affairs and business of the National Bank shall vest in a Board of Directors, which shall exercise all powers and do all acts and things which may be exercised or done by the National Bank.
     (2) Subject to the provisions of this Act, the Board in discharging its functions, shall act on business principles with due regard to public interest.
     (3) Subject to the provisions of sub-section (1) and save as otherwise provided in the regulations made under this Act, the Managing Director shall also have powers of general superintendence, direction and management of the affairs and business of the National Bank and may also exercise all powers and do all acts and things which may be exercised or done by the National Bank:
     ¹[Provided that during the period of any casual vacancy of the nature referred to in section 11 in the office of the Managing Director, the Chairman may also exercise the powers and discharge the functions of the Managing Director until the person appointed by the Central Government under section 11 to act as Managing Director enters upon his office.]
     (4) Any whole-time director appointed under sub-section (3) of section 6 shall assist the Managing Director in the discharge of his functions under sub-section (3) and perform such duties as the Board may entrust or delegate to him.
     (5) In the discharge of his powers and functions under sub-section (3), the Managing Director shall follow such directions as the Chairman may give.
     (6) In the discharge of its functions under this Act, the National Bank shall be guided by such directions in matters of policy involving public interest as the Central Government, in consultation with the Reserve Bank, or the Reserve Bank, may give in writing.