nastika vs philosophical theory

nastika and philosophical theory both are nouns.

Word	Noun	Adjective	Verb	Adverb
nastika	Yes	No	No	No
philosophical theory	Yes	No	No	No

As nouns, philosophical theory is a hypernym of nastika; that is, philosophical theory is a word with a broader meaning than nastika:

nastika: Technical term in Hinduism used to classify philosophical schools and persons that do not accept the authority of the Vedas as supreme revealed scriptures.
philosophical theory: a doctrine accepted by adherents to a philosophy

Other hypernyms of nastika include philosophical doctrine.

nastika (noun)	philosophical theory (noun)
Technical term in Hinduism used to classify philosophical schools and persons that do not accept the authority of the Vedas as supreme revealed scriptures.	a doctrine accepted by adherents to a philosophy