Following yesterday's release of developer-only previews of the upcoming iOS 10.3 and macOS Sierra 10.12.4 software updates, Apple today made the new betas available to public beta testers who are enrolled in Apple Beta Software Program.
iOS 10.3 public beta can be installed via the Software Update mechanism on iOS devices with an appropriate configuration profile installed. macOS Sierra 10.12.4 public beta can be downloaded on your Mac through Mac App Store's Updates tab.
