Yes, by default all RadEditor versions come with English (en-US), French (fr-FR) and German (de-DE) languages packs in the installation.
The content area of RadEditor is a standard editable IFRAME and if the characters are displayed properly by the browser on the same page where the editor is, they should be displayed properly in the editor as well. You should make sure that the page is saved with Unicode (UTF-8 with signature).
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