Explanation:

• Defence Minister Rajnath Singh commissioned India's attack submarine INS Khanderi into the Indian Navy in a ceremony held at the Mazagon Docks in Mumbai. • The commissioning was marked by the hoisting of the Indian National Flag on the flagpost of the submarine. • The INS Khanderi is the second attack submarine that has been commissioned into the Indian Navy under the P-75 project. • In 2017, another submarine INS Kalvari had already been inducted into the Navy. The submarine has been manufactured by Mazagon Dock Shipbuilders Limited in Mumbai.