Xcode 11.6 GM was released on 15 Jul 2020 and requires macOS 10.15.2+.
It can be downloaded from https://download.developer.apple.com/Developer_Tools/Xcode_11.6/Xcode_11.6.xip.
Release notes are located at https://developer.apple.com/documentation/xcode-release-notes/xcode-11_6-release-notes.
The SDKs it contains are:
- iOS 13.6 (Build 17G64)
- macOS 10.15.6 (Build 19G68)
- tvOS 13.4 (Build 17L255)
- watchOS 6.2 (Build 17T255)
The compilers it contains are:
- clang 11.0.3 (Build 1103.0.32.62)
- swift 5.2.4 (Build 1103.0.32.9)