These are instructions on how to root Karbonn A21 Smart (running on android 4.0) Smart Smartphone using Binary Toolkit on Windows Computer.
Requirements: Your Karbonn A21 Smart Smartphone should have at least 30-40 percent of battery to perform the rooting process.
Optional: You can also verify the root status of your device by using the Root Checker App.
[*] No data loss process: Your Phone Data like contacts, pictures, videos, music and etc will be not affected with the above method. In short, no data loss process.
[*] Phone Warranty: If you follow the above instructions your phone warranty will be void.
[*] How to unroot? To unroot your device, Open SuperSU > Settings > Full Unroot.
[*] Karbonn Stock Firmware: If you are looking for the original Stock Firmware, then head over to the Karbonn Stock Firmware page.
[*] Karbonn USB Driver: If you are looking for the original usb driver then head over to the Download Karbonn USB Driver page.