As in in pictochat and user names? If so no I don't think it is available, unless it is part of Japanese having Greek letters and the like which a quick scan says not so much. Even if you did hack it in then the games which pull from it would probably only show garbage unless you hack those as well.
If you mean in games then if you hack in the characters to the font (or again it comes as part of Japanese set -- http://www.rikai.com/library/kanjitables/kanji_codes.sjis.shtml is not always complete in games but it usually has a lot and it is not like Cyrillic is a large alphabet) there is no reason why not. Other than the Japanese stuff then you are going to have to play hacker for anything good.
Russian speaking game hackers and translators are a good bunch as well, not sure what the current sites are for Russian stuff but start with gbx.ru and go from there.
There are a handful of Russian DS games, mostl kid stuff and film tie ins.
6069 Madagascar 3 - Europe's Most Wanted Europe Eeprom - 4 kbit 512 Mbit
5254 Hardy Boys - Treasure on the Tracks, The Europe Eeprom - 512 kbit 1024 Mbit
4120 Successfully Learning Mathematics Europe Eeprom - 4 kbit 512 Mbit
3824 Disney Fairies - Tinker Bell Russia Eeprom - 64 kbit 512 Mbit
3645 Love is... ...in Bloom - The Flower Shop Garden Europe Eeprom - 4 kbit 128 Mbit
3645 Love is... ...in Bloom - The Flower Shop Garden Europe Eeprom - 4 kbit 128 Mbit
3392 Travel Coach - Europe 3 Europe Eeprom - 64 kbit 1024 Mbit
3392 Travel Coach - Europe 3 Europe Eeprom - 64 kbit 1024 Mbit
3109 Ankh - Curse of the Scarab King Europe Eeprom - 64 kbit 1024 Mbit
1367 Pirates of the Caribbean - At World's End Russia Eeprom - 4 kbit 512 Mbit
List generated from http://www.advanscene.com/
I saw the PSP has quite a few games in Russian, including some not kid ones.
If you want a hand with hacking things then my Russian is not so good these days but I remember enough of the grammar and setup that I can help there if you want, and more general hacking concepts I am fine with.
Ah OK you are making homebrew.
In that case I imagine the devkitpro devs will do anything with extended ASCII (too many different standards and it is a nightmare to keep them all in line) and it is probably all going to be unicode instead.
Afraid I have not tangled with this here, however you might like CLIRC https://code.google.com/archive/p/clircds/source/default/source which is an IRC client written by a Russian dev aiming at handling Russian characters as part of it all.
Sony made a shocking announcement today, revealing that the company plans to move away from physical game releases in the future. Citing claims of how the industry is...
Remember when you could get an Xbox Series S for $300? Those were the days. Microsoft has today announced the latest in their console price hikes, seeing their...
The delays may be behind us, but the news isn't all good for Grand Theft Auto VI. Rockstar have today announced that pre-orders for the game will go live tomorrow, on...
Last month we got confirmation of a new model of Switch 2 to better comply with upcoming EU regulations. With the legislation set to come into effect in February of...
The end has come for the PlayStation 3 and the PlayStation Vita. After supporting the PSN Store on the PS3 and PS Vita since 2006 and 2011 respectively, Sony has...
Tired of waiting for Game Freak to bring Pokemon Emerald to modern platforms? We've got you covered with a brand new port in the works. Currently available on GitHub...
In this time of economic uncertainty and rampant price hikes, the Steam sales stand as our final bastions of affordability for those opting to avoid the seas. The...
Apple have today announced price increases, primarily focused on their MacBook and iPad lines. These increases have already come into effect, with both prices and the...
For fans of Sinnoh, the pickings are slim. If you want the best experience you're left deciding between the updated region in Platinum, or the somewhat controversial...
The Switch 2 has been out for a year now, but you shouldn't count the original system out yet! Released a few days ago, popular PS2 emulator NetherSX2 has found its...
Sony made a shocking announcement today, revealing that the company plans to move away from physical game releases in the future. Citing claims of how the industry is...
Remember when you could get an Xbox Series S for $300? Those were the days. Microsoft has today announced the latest in their console price hikes, seeing their...
The delays may be behind us, but the news isn't all good for Grand Theft Auto VI. Rockstar have today announced that pre-orders for the game will go live tomorrow, on...
Last month we got confirmation of a new model of Switch 2 to better comply with upcoming EU regulations. With the legislation set to come into effect in February of...
The end has come for the PlayStation 3 and the PlayStation Vita. After supporting the PSN Store on the PS3 and PS Vita since 2006 and 2011 respectively, Sony has...
Tired of waiting for Game Freak to bring Pokemon Emerald to modern platforms? We've got you covered with a brand new port in the works. Currently available on GitHub...
Ocarina of Time is back in style as the upcoming Switch 2 remake looms on the horizon. But what's a fan of the game to do over the next few months? If you've been...
Apple have today announced price increases, primarily focused on their MacBook and iPad lines. These increases have already come into effect, with both prices and the...
In this time of economic uncertainty and rampant price hikes, the Steam sales stand as our final bastions of affordability for those opting to avoid the seas. The...
Amidst news of layoffs and cancellations in the wake of Xbox's larger changes, Bethesda has today come out with a statement discussing their active projects. In this...