As of now Redkit is only available in english and I think there will be no other languages supported by CD Projekt. Maybe some modder will take care of it.
But you can of course still change Redkit to russian in the upper panel so if you write russian dialogue, people with the language settings russian in The Witcher 2 will be able to read them.
But you can of course still change Redkit to russian in the upper panel so if you write russian dialogue, people with the language settings russian in The Witcher 2 will be able to read them.