Hindi in the Devanagari script is the official language of India. English is merely an additional official language.

Consequently both of your questions are built on a false assumption. English is not the official language and a regional language is.

Here is the governing constitutional provision straight from the Government of India's Ministry of Home Affairs' Department of Official Language's website:

http://rajbhasha.nic.in/en/constitutional-provisions

Article 343. Official language of the Union-

The official language of the Union shall be Hindi in Devnagari script. The form of numerals to be used for the official purposes of the Union shall be the international form of Indian numerals.

My apologies to the moderators if this comment does not meet the subreddit's standards for top level responses but I'm presuming that when a question is based on a misunderstanding the same standards need not be met.