Explanation:

Both statements are correct.

• The Defence Research and Development Organisation (DRDO) has taken up a preliminary study on the design and development of an indigenous conventional submarine under Project-76.

• Under Project 76, the Warship Design Bureau of the Indian Navy is working on designing and developing the country’s first indigenously conventional diesel-electric submarine. 

• The Indian Navy wants to build 12 submarines under Project 76. 

• Envisioned as air-independent propulsion (AIP)-equipped diesel-electric attack submarines, these submarines, expected to have a submerged displacement of 3,000 tons, represent a leap beyond their foreign-designed predecessors like Project-751 (India) and Project-75 submarines. 

• It aims to succeed the renowned Sindhughosh (Kilo) class, emphasizing the Navy’s commitment to maintaining a robust 3,000-ton class of submarines.

• It is expected to feature some of the most advance features such as, indigenous Weapon Control system and Lithium-ion batteries. 

Hence option 3rd is correct.