Hi there! Tajik translation for debian-installer is in an active translation and review/editing process and is nearly completed. However, I coordinate terminology and language related questions with our local language authority (the Committee of Language and Terminology by the Government of Republic of Tajikistan) to make translations officially recognized for Debian product. It may take some time, as I have some other activities in parallel. But all in-between Tajik translation updates will be committed immediately for the use.
Just for your information. Have a great day! Victor