No, it isn't. Tor is a browser and only encrypts the data transmitting through the browser. A VPN is specific privacy protection software and encrypts all data coming out of a device, whether it comes from a browser or an app. The key difference between a VPN and Tor are their operation methods.
Is Tor a good VPN?
Tor is better than a VPN for the following: Anonymously accessing the web – It's almost impossible to trace a Tor connection back to the original user. You can safely visit a website without leaving any identifying evidence behind, both on your device and on the website's server.
Does Tor work without VPN?
Yes you can use TOR without VPN but with VPN it will give you a extra security, anonymity and you can be more safe while browsing on dark web.