Cape Comorin was the name given to the sourthern tip of Hindoostan. It was located between the Arabian Sea to the west, and the Bay of Bengal to the east. Directly east of Cape Comorin, across short sea channel, was the island of Ceylon.
Cape Comorin appeared on a map of the region in 1904. (TV: Survivors of the Flux [+]Chris Chibnall, Doctor Who series 13 (BBC One and BBC America, 2021).)