Try The Redstone Land maybe? Its probably the longest running Gregtech-6 server and the map has never been reset since 2016.
IP: hsdl.xhub.win
You will need to download the client from here to join the server:
Most content are in Chinese but I’m thinking of repack the client and rewrite all the wiki pages if there are more English speaking players show up.
BTW the server is in the U.S.