After the earlier release of public iOS 10.3.2 beta 2 bringing back support to 32 bit devices like iPhone 5,5C with bug fixes and improvements, Apple has released iOS 10.3.2 beta 3 along with beta 3rd of macOS Sierra 10.12.5, watchOS 3.2.2, and tvOS 10.2.1.
iOS 10.3.2 Developers Beta 3 is available for download to registered developer’s via OTA over-the-air on iPhone 7- 7 Plus and other compatible devices like iPhone 6s-Plus, iPhone 6 – Plus-,iPhone 5S-SE from iOS settings app running previous beta or you can download iOS 10.3.2 Beta 3 through Apple’s online developer center and Apple Beta Software Program.
In case of mac, macOS Sierra 10.12.5 can be installed through Mac App Store’s Updates tab. For Apple TV, tvOS 10.3.2 beta 3 can be
installed in Settings → System → Software Updates → Update Software and Apple Watch, watchOS 3.2.2 beta 3
can be installed with the Watch app on your iPhone by tapping My Watch →
General → Software Update.