tvOS doesn't have public code names the way the Mac does, but it does have internal code names all its own.

Only macOS has public code names — currently based on California landmarks like Sierra. The rest do have secret code names, however. While both tvOS and watchOS are based on iOS, where watchOS got to start over at version 1.0 and its own beach-themed code names, tvOS kept going at 9.0 and the same code name as iOS. The numbering has continued to keep pace, but the code names have started to go their own way.

  • 9.0: Monarch
  • 9.1: Tilden
  • 9.2: Angora
  • 10.0: Union

More code names

Via: iPhone Wiki