Here's why:
* "A" is usually transliterated as "О" (O) in Russian, except in some specific cases like "aunt" or "August".
* "U" is usually transliterated as "У" (U) in Russian.
* "St" is usually transliterated as "ст" (st) in Russian.
* "In" is usually transliterated as "ин" (in) in Russian.
Therefore, the most accurate and widely accepted transliteration of "Austin" in Russian is Остин (Ostin).