You'd need to ask the staff at those private trackers.
I think the expectation is that you may want to browse the site using the same IP address(s) that you are running your torrent client(s) on. e.g. if you are already using a seedbox/VPN/proxy then those particular trackers allow you to browse the site using that same IP address from the seedbox/VPN/proxy you are torrenting with.
They probably aren't expecting you to browse the site with some random open proxy, Tor, etc. & may end up banning you if they see those random IPs show up.