Lemmy.ml, the most popular instance fo Lemmy out there, is not accessible in my country unless I use a VPN. But, I can subscribe to any community that exists on lemmy.ml from here and even post on those communities from this account.
I love this aspect of Lemmy.
You’ll likely get a permanent redirect to some government site telling you access is denied. The same thing happens on a corporate or school network that blocked a domain.