The southernmost tip of mainland India is:

Chennai
Rameswaram
Kanyakumari
Kovalam

The southernmost tip of mainland India is Kanyakumari. It is a town in the Kanyakumari district of Tamil Nadu, India. It is located at the confluence of the Bay of Bengal, the Arabian Sea, and the Indian Ocean. Kanyakumari is a popular tourist destination, known for its beaches, temples, and churches.

Chennai is the capital of Tamil Nadu and the sixth largest city in India. It is located on the Coromandel Coast of the Bay of Bengal. Chennai is a major commercial and industrial center, and is home to many industries, including textiles, automobiles, and electronics.

Rameswaram is a town in the Ramanathapuram district of Tamil Nadu, India. It is located on Pamban Island, which is separated from the mainland by the Pamban Bridge. Rameswaram is a popular Hindu pilgrimage site, and is home to the Ramanathaswamy Temple, one of the largest Hindu temples in India.

Kovalam is a town in the Thiruvananthapuram district of Kerala, India. It is located on the Arabian Sea coast, about 16 kilometers from Thiruvananthapuram. Kovalam is a popular tourist destination, known for its beaches, resorts, and Ayurveda centers.