is it possible to join PC to domain over some VPN (eoip, wireguard ...) ?
on both side we have public IP on mikrotik.
Yes, it is. However, keep in mind that this tunnel should be site-to-site so both sides can establish any necessary connection. Also, You might wanna check your DNS config at AD, and MTs this was something that I played for around 4 hours to get it to work properly.Is it possible to make him part of domain over some VPN solution ?
I made a EOIP in which I got that DHCP from MT1 assigns addresses to devices on MT2.PC2 should resolve AD domain name via DNS to join domain. It is easier if all traffic from PC2 to Internet goes trough VPN, in this case use AD DNS in PC2 network settings. If not, you can use static DNS entries in Mikrotik to forward DNS queries for AD domain to specific servers.