iOS 15.7.4 (build 19H321) is an official Apple over-the-air update for the iPhone 6s, released on 2023-03-27T17:12:46Z. The update package is 1.18 GB. This is a delta (partial) update that requires 15.3.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 9fa30c719902552bd470c3f509f214990c07d714.zip.