Hi,
There is no such thing like "template supports a font". A template can't support or not-support a Font-Family. But Font-Family supports or not-support non-latin characters. Since you are saying, your website is in Russian, probably you are trying to use a Font-Family that supports only Latin characters.
CoolMart comes with several font-family. There are around 10 or 15 different font-family available to use right away. But you can add any Google Font you would like to CoolMart.
Browse the Google Font library:
www.google.com/fonts
and pick a font type that supports Russian letters.
Then check this Forum Topic below:
www.flexiblewebdesign.com/forum-joomla-virtuemart-template-coolmart-support/1594-extra-google-font#7470
to install that NEW Google Font to CoolMart
Regards,
Support