Since jailbreak for iOS 10.2.1 is not yet available, you can downgrade your iPhone-iPad from iOS 10.2.1 to iOS 10.2 as earliest for future jailbreak because Apple might stops signing the iOS 10.2 in the coming days that is you cannot downgrade back iOS 10.2.1 to iOS 10.2 if Apple stops signing in that iOS version.
If you do not care about Jailbreak then you can upgrade to iOS 10.2.1 at any time. Click here to see How to install iOS 10.2.1 on iPhone, iPad and iPod Touch
First of all, you need to download the iOS 10.2 firmware file for your device from our Download page.
- You need to upgrade or download iTunes to the latest version on your Mac or PC.
- Now Turn off Find my iPhone & disable passcode lock via the Settings app. (Settings > iCloud > Find my iPhone).
- Launch iTunes & connect your iPhone, iPad & iPod Touch using data cable to your computer.
- Hold the Alt/Option key on the Mac or Shift Key in Windows on your keyboard.
- Now Select the iOS 10.2 ipsw file you had downloaded earlier.
- Then click on the Restore iPhone.
- iTunes will inform that it will restore your iOS device to iOS 10.2 and Click Restore.
- After restored, your device will reboot to the welcome screen and will now install iOS 10.2 on your device.