Again we are gonna teach you how to downgrade ios 9.2.1 to ios 9.0.1. I will show you this downgrade as step by step. You can do it easily by following this article.
Firstly you need computer which is runing Mac or Windows. and it must be has iTune installed. If you already install it you don’t want install iTune again. If still you have not that application in your pc please download iTune application by below download link and install it.
Keep in your mind please sign out iCould on your iDevice. and you need to download ipsw restore firmware to pc wich has windows or mac OS. You can download IPSW restore firmware from below link and keep in your mind you just need to select correct ipsw firmware before you download.
As a second step you just need to connect your ios 9.2.1 jailbreak iDevice to your pc that have installed iTune. And it will take few seconds to detect your iDevice. And as a step three you will receive restore to your iDevice. Then you need to click restore and update button of iTune window.
In this step, if you are windows user you just need to click restore button with shift key of the keyboard. And same as above if you are a mac user, Please click restore button with option key. And after that iTune will give you another window to go next step. Then iTune will receive window to select firmware (ios 9.0.1 firmware). Please select ipsw restore firmware which is you download in above step. Then click restore button.
It will take several time to process. so please wait. After that process your iDevice will reboot automatically and after the restart, You can check your ios version on your iDevice setting and then enjoy on ios 9.0.1 again.