A type of millets extensively cultivated in Tamil Nadu is:

Kodo millet
Foxtail millet
Little Millet
Pearl Millet

The correct answer is Pearl Millet.

Pearl millet is a type of millet that is extensively cultivated in Tamil Nadu. It is a small, round grain that is high in protein and fiber. It is a staple food in many parts of the world, and is used to make a variety of dishes, including porridge, bread, and pancakes.

Kodo millet is a type of millet that is not as widely cultivated as pearl millet. It is a small, dark grain that is high in carbohydrates and fiber. It is used to make a variety of dishes, including porridge, bread, and pancakes.

Foxtail millet is a type of millet that is not as widely cultivated as pearl millet or kodo millet. It is a small, yellow grain that is high in carbohydrates and fiber. It is used to make a variety of dishes, including porridge, bread, and pancakes.

Little millet is a type of millet that is not as widely cultivated as pearl millet, kodo millet, or foxtail millet. It is a small, white grain that is high in carbohydrates and fiber. It is used to make a variety of dishes, including porridge, bread, and pancakes.

Pearl millet is the most widely cultivated type of millet in Tamil Nadu. It is a staple food in the state, and is used to make a variety of dishes. It is a good source of protein, fiber, and vitamins.