The Not Registered On Network issue is most commonly caused by faulty imei, dial *#06# to see if your imei corresponds to that on your phone sticker under the battery.
1. Download Busy box on Play Store & install it on your Note pad.
2. Download Ariza Patch apk on google & install it on your Note pad.
3. Remove Simcard from your Note pad.
4. Open Ariza to patch your Note pad.
5. Re-insert SImcard to check Network.
I will edit the post later to include the download links + detailed explanatons In Shaa Allah.