Add russian locale to debian
locale
LANG
Edit /etc/default/locale and set the contents to:
LANG="ru_RU.UTF-8"
You can check which locales you currently have generated using:
locale -a
You can generate more by editing /etc/locale.gen and uncommenting the lines for the locales that you want to enable. Then you can generate them by running:
locale-gen
You can find a list of supported locales in /usr/share/i18n/SUPPORTED