-first of all put the ROM zip in the root of your SD card, (no folder at all)

-after which boot your device into TWRP recovery

-after which navigate to wipe system>> wipe cache>>wipe dalvik

-now go back and navigate to the SD card to select the ROM and click on yes.

Also Check: Download Infinix Hot 4 x557 Stock Rom Firmware

NOTE:
First boot takes about 5 to 10 minutes for ROM to bootup

FAQs
Always make a backup of your phone it is possible that something might go wrong.

ROM OS Version: 6.0.x Lollipop
ROM Kernel: Linux 3.18.x
ROM Firmware Required: TWRP

Version Information:
Status: Stable
Current Stable Version: V1.0
Stable Release Date: 2016-09-12

Downloads:
Hasee Rom For Infinix Hot 4

TWRP Here