We have a list of Tor relays here. That said, most of them are clearnet + tor.

GitHub

GitHub - 0xtrr/onion-service-nostr-relays: A list of nostr relays exposed as onion services

A list of nostr relays exposed as onion services. Contribute to 0xtrr/onion-service-nostr-relays development by creating an account on GitHub.

There is also a (tiny) list of clients available over Tor here:

GitHub

GitHub - 0xtrr/onion-service-nostr-clients: A list of nostr clients exposed as onion services

A list of nostr clients exposed as onion services. Contribute to 0xtrr/onion-service-nostr-clients development by creating an account on GitHub.