, follow this guide. This specific model is a 32-bit device, and iOS 9.3.5 (or 9.3.6 for certain cellular models) is the final supported version. 1. Download the Firmware (IPSW File)
Ensure your data is backed up via iCloud or a local computer. Charge: Keep your iPad connected to a power source. Download iOS 9.3.5 for iPad Mini model iPad2,7 ...
You can download the specific firmware file from verified repositories that link directly to Apple's servers: iPad2,7_9.3.5_13G36_Restore.ipsw Download Source: Use IPSW Downloads or iClarified to find the " iPad mini (CDMA/Global) Go to product viewer dialog for this item. " 9.3.5 file. , follow this guide