varna vs grouping

varna and grouping both are nouns.

Word	Noun	Adjective	Verb	Adverb
varna	Yes	No	No	No
grouping	Yes	No	No	No

As nouns, grouping is a hypernym of varna; that is, grouping is a word with a broader meaning than varna:

varna: (Hinduism) the name for the original social division of Vedic people into four groups (which are subdivided into thousands of jatis)
grouping: any number of entities (members) considered as a unit

Other hypernyms of varna include group.

varna (noun)	grouping (noun)
(Hinduism) the name for the original social division of Vedic people into four groups (which are subdivided into thousands of jatis)	any number of entities (members) considered as a unit
	the activity of putting things together in groups
	a system for classifying things into groups