To use the Tor browser, you'll need to install the torbrowser-launcher package. Installing will pull in the required dependencies as well (tor and other stuff).
You can either do it via the software center, or use this command sudo eopkg it torbrowser-launcher.
Regarding Brave, it's included in the Solus repos as well (as is Telegram, If you wanted to see If the app still works).
If I were you, I'd try saving up some money and pick up some yearly / bi-yearly proper VPN plan. Fortunately, the internet situation in my country is not as draconian, so I was not forced to pick up a VPN, but I'd certainly do it if I were in your shoes.
ProtonVPN is a good one, or so I've heard. You can even use the official clients easily on Solus, as they're included in the repos. The only downside is that it's quite pricey.
