+ This site is so good to know that torrent tracker is open for sign up and what is open for donation sign up
- Also has information about tracker which open their sign up for limited account in specific period in the year / month
https://opentrackers.org/
+there is forum in invitehawk that either post information about open for sign up tracker
https://www.invitehawk.com/forum/44-open-signup-tracker-updates/
+ Also there is a Reddit community is called OpenSignups
https://www.reddit.com/r/OpenSignups/