Quechua vs American Indian

Quechua and American Indian both are nouns.

Word	Noun	Adjective	Verb	Adverb
Quechua	Yes	No	No	No
American Indian	Yes	No	No	No

As nouns, American Indian is a hypernym of Quechua; that is, American Indian is a word with a broader meaning than Quechua:

Quechua (noun)	American Indian (noun)
the language of the Quechua which was spoken by the Incas	any of the languages spoken by Amerindians
a community of South American Indians in Peru who were formerly the ruling class of the Incan Empire
a member of a South American Indian people in Peru who were formerly the ruling class of the Inca empire