Once you understand basic flashing, you should abandon stock firmware entirely. Here are the best community builds:
Appendices
If you have a different "X6" device (e.g., an X6 TV box or a completely different brand), please clarify, as the advice above applies only to the common retro gaming handheld. X6 Game Console Firmware
Disclaimer: Modifying firmware voids your warranty. Always back up your original NAND dump before flashing. This article is for educational purposes for users who own the hardware. Once you understand basic flashing, you should abandon