The term 'India' originates from the River Indus, which was surrounded by the habitats of ancient settlers. The early Aryan inhabitants initially called this river the Sindhu, while Persian invaders later transformed it into 'Hindu'.
The name "India" was legally adopted as the official name of the country on January 26, 1950, when the Constitution of India came into effect, marking the country's transformation into a republic.
The name "India" as a geographical and historical reference predates British colonial rule. It has ancient origins and is derived from the River Indus, which has been significant in the region's history. The British did not invent the name "India." Instead, they adopted and popularized it during their colonial rule
The specific article in which the name is mentioned is Article 1 of the Indian Constitution. Article 1 states:"India, that is Bharat, shall be a Union of States."