In short words, his the only option at this point is to use thingy called zapret (if for whatever fucking reason, living in Russia, he still doesn't know what it is). And it is important to download that thing only from Flowseal's repository (32k stars currently). Others - very high chance to be a scam.

If he already use it, and it doesn't really help, then he needs to change some settings. I personaly use: Gamefilter - TCP + UDP, ip-set - any (without them i couldn't connect to any server). And for bat files - EXP or ALT9.

But, shit is inconsistent, and really depends on where he lives and what ISP hes using. So if my settings don't work - experiment with others, ask other folk in git-hub discussions, or ask AI.