Which of the following islands is the southernmost point of India?

The correct option is Indira Point.

Let's understand the geography of India's southernmost points step-by-step:
1. Mainland Southernmost Point: The southernmost point of the Indian mainland is Cape Comorin (Kanyakumari), located in Tamil Nadu at approximately $8^{\circ }{4}^{\prime }\text{N}$ latitude.
2. Overall Southernmost Point (Including Islands): When considering the entire territory of India, including its island territories, the southernmost point lies further south in the Andaman and Nicobar Islands.
3. Indira Point: Located on Great Nicobar Island, Indira Point is situated at approximately $6^{\circ }{45}^{\prime }\text{N}$ latitude. This makes it the absolute southernmost point of the Republic of India.
4. Comparing the Options:
- Kavaratti: The capital of Lakshadweep, located in the Arabian Sea (much further north and west).
- Little Andaman: Part of the Andaman archipelago, located north of the Nicobar group.
- Car Nicobar: The northernmost of the Nicobar Islands.
- Indira Point: Located at the southern tip of Great Nicobar Island, which is the southernmost island of the Nicobar chain.

Therefore, Indira Point is the southernmost point of India.