Instead of downloading pre-made .rar files from the internet, the to root an Infinix X663 Download the Official Stock ROM for your specific build. Extract the boot.img yourself. Patch it using the Magisk App on your phone. Flash the patched file via Fastboot on a PC.
If the firmware version (V686) does not exactly match your current build version, flashing this file can "brick" your device (rendering it unusable). Download Root X663 V686 Firmware4Mobile com rar
You may see a "Red State" or "Orange State" warning on boot, preventing the OS from loading. Instead of downloading pre-made
You cannot flash "Root" files unless your bootloader is already unlocked (this wipes all data). Flash the patched file via Fastboot on a PC
Files hosted on .com.rar archives from unofficial blogs are not verified. They may contain malware or "backdoor" scripts that compromise your phone's data.