All the devices that support iOS 9 are eligible for Jailbreak. Supported iOS are 9.0.1 and 9.0.2; that means if you are using the public beta version of iOS 9.1, you will not be able to Jailbreak it. You can restore from a backup and get back to iOS 9.0.2 if you are so anxious to Jailbreak you iDevice.
You can download the jailbreak tool from here for Windows PC. There is no official word from Pangu, on when Mac users will be receiving this tool.
The big question is, whether users should Jailbreak iOS 9.0.2 as iOS 9.1 public version is expected anytime soon. We can also expect Apple to counter the Jailbreak exploit in their next update as iOS 9.1 is still under beta.