How to unroot your android mobile and tablet.

1
Open a root file manager on your device. There are lots of different file managers available on the Play Store that you can use to browse your Android device’s root files. Popular file managers include Root Browser, ES File Explorer, and X-Plore File Manager.
2
Navigate to /system/bin/. Find and delete the file named su. You can press and hold on the file and then select “Delete” from the menu that appears. There may not be a su file here depending on how you rooted your device.
3
Navigate to /system/xbin/. Delete the su file here as well.
4
Navigate to /system/app/. Delete the Superuser/kinguser.apk file.
5
Reboot your device. The above method should unroot your device after you reboot.