Torrentz2 says at https://torrentz2.eu/help that following torrent indexes are largest when it comes to a torrent count:

http://monova.org 64,253,514 torrents (can not add torrent, adblock block it)
http://btdb.to 53,435,850 torrents (can not add torrent)
http://torrentdownloads.me 15,751,641 torrents (can not login account)
http://bittorrent.am 11,396,220 torrents - (can not add torrent)
http://idope.se 17,472,836 torrents (registration, torrent adding WORKS)
http://limetorrents.cc 9,776,911 torrents (registration e-mail not arrive)
http://torrentfunk2.com 9,918,795 torrents (offline)
http://torrentdownload.ch 9,923,282 torrents (registration not working)
http://seedpeer.eu 9,051,013 torrents (registration, torrent adding WORKS)
http://bt-scene.cc 4,953,574 torrents (WORKS, but has to e-mail admin to upload torrents)
http://torlock2.com 4,234,776 torrents (registration not working)
http://1337x.to 2,328,102 torrents (WORKS)
https://thepiratebay.org ? torrents (WORKS)

most of these do not work to submit torrent. I highlighted ones that works. What are other open trackers that gets indexed in torrent meta-search engines like torrentz2.eu and allows adding torrent + have many torrents?