I'm translating English to Hindi, what's it called when the translations are with English characters?

Transliteration may be the word you're looking for: "Pyāra" is the transliteration of "प्यार" into the Latin alphabet.

From Wikipedia:

Transliteration is the conversion of a text from one script to another.

For instance, a Latin transliteration of the Greek phrase "Ελληνική Δημοκρατία", usually translated as 'Hellenic Republic', is "Ellēnikḗ Dēmokratía".

I believe you are looking for

Romanization

From the romanization wikipedia,

Romanization or Latinization (or romanisation, latinisation: see spelling differences), in linguistics, is the conversion of writing from a different writing system to the Roman (Latin) script, or a system for doing so. Methods of romanization include transliteration, for representing written text, and transcription, for representing the spoken word, and combinations of both.