Is it possible to release the iOS app as an open beta in App Store? Use case: anyone can download the app through the Apps Store without having any registration ( same as play store beta release)
Unfortunately your question is self-contradictory in the context of the App Store.
An app can either be released to the App Store or it can be in test/beta but it can't be both.
You can provide open beta access via a TestFlight link, but you need to find your own way of sharing this link (via your web site, for example).
Only fully functional apps will be approved for App Store release to ensure that users have a good experience with App Store apps. Any mention of "beta" or "test" will result in rejection.