Disqus is translated into other languages with Transifex, the crowdsource translation service that we use to offer translations of the Disqus embed. If you’d like to help us review the translation to make it available for use, you can do so by following the steps outlined here: https://help.disqus.com/customer/portal/articles/466219-translating-disqus#translate
If you’re interested in the status of your language (or others) please see our Translation Status page here: https://www.transifex.com/projects/p/disqus/resource/js/
An additional detail to note: whenever new Disqus features are added, additional strings are added to Transifex which require translation and review.
Forums which are already using a given language will still be able to use the language even if it drops below the review threshold for availability, but new forums will need to wait until the desired language is translated and reviewed above 75% in Transifex before they can select it from the drop-down.
