Indian rice vs food grain

Indian rice and food grain both are nouns.

Word	Noun	Adjective	Verb	Adverb
Indian rice	Yes	No	No	No
food grain	Yes	No	No	No

As nouns, food grain is a hypernym of Indian rice; that is, food grain is a word with a broader meaning than Indian rice:

Other hypernyms of Indian rice include cereal, grain.

Indian rice (noun)	food grain (noun)
grains of aquatic grass of North America	foodstuff prepared from the starchy grains of cereal grasses