But for serious privacy work in 2024? You really need to upgrade your OS or use Tails (a USB-bootable OS). The internet has moved on, and so have the exploits.
Navigate to the official Tor Project Archive: https://archive.torproject.org/tor-package-archive/torbrowser/10.5.11/ tor browser for el capitan
Still, for one nostalgic evening on a classic Mac? Fire up Tor Browser 10.5.11 and take a trip back to a simpler, slower web. But for serious privacy work in 2024