Hi,
If the theme Eguru is a theme you can download from the Plugins repository then there will be a theme_eguru.php already in thr AMOS Translations, but perhaps not yet translated.
All Language translations other than English are managed via AMOS. You will find a link to the Moodle Translation site at the top of this page.
Here is that link...
You can login and then follow the instructions to find the Turkish language file theme_eguru.php so that you can add the translations.
Hope this helps?
Cheers,
Mary