Transliteration is a mapping from one system of writing into another, in our case from Telugu to Roman script. There are severals standards that developed over time. Here is an arbitraty selection of some of them used for Telugu:
ISO 15919 Transliteration of Devanagari and related Indic scripts into Latin characters is an international standard for the transliteration of Indic scripts to the Latin alphabet formed in 2001. It uses diacritics to map the much larger set of Brahmic consonants and vowels to the Latin script.
The International Phonetic Alphabet (IPA) is a system of phonetic notation based on the Latin alphabet, devised by the International Phonetic Association.
Online-tool to convert english to Telugu script and back. Also available for Bengali, Gujarati, Hindi, Kannada, Malayalam Marathi, Nepali, and Tamil.
Online-tool to convert english tansliteration to Telugu script. Includes a virtual Telugu keyboard.
Another English-to-Telugu converter.
A Telugu to English transliteration.