Indian vs Assamese

Indian and Assamese both are nouns.

Word	Noun	Adjective	Verb	Adverb
Indian	Yes	Yes	No	No
Assamese	Yes	Yes	No	No

As nouns, Assamese is a hyponym of Indian; that is, Assamese is a word with a more specific, narrower meaning than Indian:

Indian (noun)	Assamese (noun)
any of the languages spoken by Amerindians	the Magadhan language spoken by the Assamese people; closely related to Bengali
a native or inhabitant of India	native or inhabitant of the state of Assam in northeastern India

Indian (adjective)	Assamese (adjective)
of or relating to or characteristic of India or the East Indies or their peoples or languages or cultures	of or relating to or characteristic of Assam or its people or culture or language
of or pertaining to Native Americans or their culture or languages