Indian vs Panjabi

Indian and Panjabi both are nouns.

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

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

Indian (noun)	Panjabi (noun)
any of the languages spoken by Amerindians	the Indic language spoken by people in Pakistan and Punjab
a native or inhabitant of India	a member of the people of Pakistan and Punjab

Indian (adjective)	Panjabi (adjective)
of or relating to or characteristic of India or the East Indies or their peoples or languages or cultures
of or pertaining to Native Americans or their culture or languages