iOS 17
Developers taking part in Apple’s beta program can get the latest builds from the Apple Developer Center or by simply updating their iPhone or iPad that are already running the betas, using the Settings app. Public beta versions generally appear not long after the developer versions, and can be signed up to via the Apple Beta Software Program website.
The release candidates for iOS 17.5, iPadOS 17.5, tvOS 17.5, watchOS 10.5, and macOS Sonoma 14.5 turn up after the fourth betas, which Apple brought out on April 30. The third round was on April 23, the second on April 16, and the first surfaced on April 2.