India's first nuclear submarine is INS Arihant. It is a nuclear-powered ballistic missile submarine (SSBN) that was launched on July 26, 2009 and commissioned into the Indian Navy on August 10, 2016.

• INS Arihant is the first nuclear submarine designed and built by India. It is 111 meters long and has a displacement of 6,000 tonnes. It is powered by a pressurized water reactor and can carry up to 12 K-15 Sagarika ballistic missiles, which have a range of over 700 kilometers.
• INS Arihant is a significant milestone in India's nuclear program and its development as a major maritime power. It gives India the ability to launch nuclear missiles from sea, which is a key component of a nuclear triad.
• The commissioning of INS Arihant completed India's nuclear triad, which means that India can now deliver nuclear weapons by air, land, and sea. This gives India a more credible deterrent against nuclear attack and strengthens its national security.