Definitions for South Asia are varying and could be Thailand, Malaysia, Indonesia, or India.
India is the largest country in South Asia.
Asia
South.
It is just a geographical term for the southern part of Asia, so it is not a country.
technically it is the Indian subcontinent, or south Asia
depends on which country in south east Asia
Afghanistan is the county in South Asia with the lowest life expectancy. The country in South Asia with the smallest population is Maldives.
India
South Central country.
Southeast Asia is made up of many small countries, so to answer your question we need the name of a country.
Induia
South of Asia