Download Gionee F103B (GN3003) firmware from the link here, and follow the provided flashing instructions to learn how to flash the stock rom.
If you notice that any of the links provided below is broken or doesn’t work, please post in comments section so we fix and update it ASAP.
File Name: Gionee_GN3003-F103B-171008-SGzip.zip
Size: 1.2 GB
Firmware – Download
How to flash
After downloading the above firmware, copy to the root of your phone’s storage and reboot the phone to recovery mode.
Select Install zip from sdcard and choose the downloaded file on your sdcard.
Confirm to begin installation and wait patiently for the process to complete.
Once done, reboot and enjoy!