Out of many republics that are most likely to break away from the Russian Federation is Caucasus. There are quite high chances of Caucasus Republics to break away from Russian Federation sooner or later, it does not matter if Russian wins the war or not.
This is very volatile region and Russia is running war there continuously with variant intensity for the last 20 years. Chechnya is only nominally part of Russia with local warlord Kadyriov being loyal to Putin mostly because of Russian money and Putin military support for Kadyriov against his own people.
Some of the O-blasts will split into pieces as well and secede from the Matuschka. The current anti-fascist sanctions will become a game changer for independentist movements across and within the Russian Federation.
The first two to go will be Içkeria (Tchetchnja) and Karelia, which the latter will join forces with Finland, Sweden and Norway and along with Denmark, Greenland and Iceland will create a new Nordic Union based on economic and military cooperation. Soon after the rest of Russian Finnic republics such as Udmurtia, Komi, Chuvashia, Mari-El will secede and create a Confederation with economic union with the Nordic Union where Karelia will already be a member of.
Then Tatarstan (Kazañ) will secede and will invade Crimea claiming it as their own. Then Preussen (Königsberg) known as “kaliningrad” will secede and will become a newly independent Russian republic just like Taiwan (China) and will follow cultural principles of the old Baltic Prussians. After those the Republic Sakha (Yakutia) will secede and create a new separate state in Northern Asia which is rich in natural gas, oil etc.
Buriatia, Tuva, Khakassia and Altai will secede and create a Confederation, which will join with Mongolia in a new economic and political union. Finally a Republic of Ingria will be created with St. Petersburg as it’s capital leaving the rest of Russia without access to the Baltic Sea. Grossly reduced in economic and political power Russian Federation or what’s left of it will forever lose their imperial ambitions.
There will be a land grab in the Russian Far East, which will end up under Chinese rule, but the Sakhalin and Kamchatka will be sold to the Japanese at an undisclosed amount, with the entire chain of Kuril islands included as a bonus to the deal. Chukotka will join Sakha (Yakutia) in a newly formed Federative Republic.