I have the latest Xcode 8 beta 6 but I do not see any iOS 10 simulators. When I try to add one, I do not have the option to select iOS 10:
I tried removing and re-installing XCode 8 but it does not help.
The content of /Library/Developer/CoreSimulator/Profiles/Runtimes/ does indeed not show the iOS 10 runtime
ll /Library/Developer/CoreSimulator/Profiles/Runtimes/
drwxr-xr-x@ 4 root wheel 136 May 5 08:53 iOS 7.1.simruntime
drwxrwxr-t 3 root admin 102 Aug 22 13:51 iOS 8.4.simruntime
drwxrwxr-t 3 root admin 102 Jul 12 08:30 iOS 9.3.simruntime
I was facing the same issue:
Basically iPhone 4S doesn't support iOS 10. Its architecture is unsupported. So you can select any device from iPhone 5 onwards.
Please find screenshots below for reference:
iPhone 4S & iPhone 6S
Cheers!