The principal official language of the Republic of India is Standard Hindi, while English is the secondary official language.
At present there are 22 languages recognized by the Constitution of India, Hindi being the most widespread language amongst all. The native speakers of Hindi account for about 43% of Indians.
These languages are the official languages of individual states, divided as per socio-linguistic borders.
If you want your message to reach the vast non-English speaking population of India, translation into Indian languages will definitely be of great help!