coastal plains

 The land along an ocean, a sea or bay is called a coast. The boundary of coast, where land meets water, is called coastline.

there are two coastal plains in India eastern coastal plains and western coastal plains

 the eastern coastal plains in the east and  western coastal plains in the west

the eastern coastal plains lies in bay of Bengal and the western coastal plains lies in Arabian sea

the two coastal plains meets in Kanyakumari in Indian ocean