iOS 12.1 (build 16B92) is an official Apple over-the-air update for the iPhone 6s, released on 2018-10-30T17:16:59Z. The update package is 1.35 GB. This is a delta (partial) update that requires 11.1.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 210ba436d0a665937484d924100d9c164ee2c99e.zip.