Apple has released iOS 13 beta 6 to developers for testing with the build number is 17A5556d, a week after the release fo iOS 13 beta 5 . iOS 13 beta 6 comes with lots of bug fixes and improvements along with the new features like Dark Mode in Control Center Toggle, Folder Transparency in Homescreen, Hide Link Previews in Safari, Three Finger Tap for undo, redo, cut, copy and paste and more.
Along with that iOS 13 introduces new features like Dark Mode, new browsing and editing tools for Photos, Sign in With Apple, enhancements to Maps, updates to Reminders, Notes, Messages, Siri, CarPlay, Files, and much more. More details here
Downloading and Installing iOS 13 Developer beta 6
The registered developers can download and try the iOS 13 beta 6 from Apple Developer Center or via OTA(over-the-air) mechanism with the proper configuration profile that can be installed from the Developer Center.