I think you're looking for a way to geo-block your site or service to Russian IPs only, but I gotta warn you, that's a tough one to achieve. You could try using MaxMind's geolocation database or IP2Location to filter out IPs, but keep in mind it's not foolproof.
"Hey guys, you're asking how to restrict access to your site to only Russian IPs. There's a service called IP2Location that provides accurate geolocation data, including IP addresses. You can integrate it with your server to block or whitelist specific regions."