iPadOS 6.1.3 (build 10B329) is an official Apple over-the-air update for the iPad 4 (GSM). The update package is 32.76 MB. This is a delta (partial) update that requires 6.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 44abc1a250ccb6cd2982681c21e8e501d0c7b596.zip.