Tor Browser is anonymous in terms of hiding your location and browsing activity — but there are limits. Although they can't see your browsing activity or Tor encrypted data, your ISP can still see that you're using Tor.
Can ISP see Tor data?
Your Internet service provider (ISP) and local network can see that you connect to the Tor network. They still cannot know what sites you visit. To hide that you connect to Tor, you can use a Tor bridge.
Does Tor block your ISP?
Yes, the Tor browser hides activities from ISPs. However, VPNs encrypt traffic before it even reaches your ISP. So while Tor may make it more difficult for your ISP to see what you're doing online, a VPN will make it impossible.