India vs Republic of India

India and Republic of India both are nouns.

Word	Noun	Adjective	Verb	Adverb
India	Yes	No	No	No
Republic of India	Yes	No	No	No

As nouns, India and Republic of India are synonyms defined as:

India and Republic of India: a republic in the Asian subcontinent in southern Asia; second most populous country in the world; achieved independence from the United Kingdom in 1947

Other synonyms of India include Bharat.

India (noun)	Republic of India (noun)
a republic in the Asian subcontinent in southern Asia; second most populous country in the world; achieved independence from the United Kingdom in 1947	a republic in the Asian subcontinent in southern Asia; second most populous country in the world; achieved independence from the United Kingdom in 1947