The correct option is D About 6100 km
Length of Coastline of Indian mainland is 6100 km. Length of coastline of India including the coastline of Andaman and Nicobar Islands in the Bay of Bengal and Lakshwadeep Islands in the Arabian Sea is 7517 km. Coastline of Indian mainland is surrounded by Arabian Sea in the west, Bay of Bengal in the east , and Indian Ocean in the south.