The region of the iTunes Store that you have access to, is determined by the region of your Apple ID account and its billing address and its local payment method. You can’t change that to a different country at will, without changing everything for your account.
The available languages are determined by the supplying studio (here: Universal Studios), not Apple, and tailored to the local customers. You may want to contact the responsible studio to express your interest in original language audio in your region for iTunes Store titles.
You can check the supported languages for any of the titles from Apple from the movie’s information page, before you ruches or rent.
Despicable Me 3 - iTunes Preview - Apple (web-version of the information page)
Languages:
• Primary: Arabic (Stereo, Dolby)
(no other languages)