Key rules
Russia
It operates under Presidential Decree No. 637 (2006), amended by Decree No. 634 of 8 September 2025: a document proving knowledge of Russian is required, and if you leave the region within 3 years, the costs may be recovered. You apply at the consulate or the Ministry of Internal Affairs (МВД, MVD) of the chosen region. The rules change, so check the MVD website and Gosuslugi (Госуслуги).
Sources: Ministry of Internal Affairs of Russia («МВД России», мвд.рф): migration services, Gosuslugi («Госуслуги»)