There are two major steps here:>>Follow this steps to unlock your Bootloader of Gionee Elife S Plus HERE
>>Flashing the TWRP recovery.img and SuperSU method.
After rooting your phone, it’s advisable to unroot before performing an OTA update.
Materials Needed For Rooting
» PC with internet connection
» USB Cable
» SP Flash Tool - Download it Here
» SuperSU.zip - Download it Here
» For Gionee Elife S Plus, download Ported CWM by Team Hovatek - Download it Here
» download Ported TWRP by Team Hovatek - Download it Here
To Root Gionee Elife S Plus or Gionee Pioneer P5W
» Save the SuperSU.zip that you downloaded to your phone's SD card
» Unzip the TWRP zip file that you downloaded and flash the recovery image to the phone using SP Flash Tool
How Can I Flash it Using SP Flashtool? follow this instruction: Here
» Now, boot your phone into TWRP Recovery Mode (by Holding the Vol Up and Power button simultaneously for 5 seconds)
» In TWRP Recovery, Choose install zip from SD card - to choose a zip from SD card use Vol up and down scroll up and down, then choose the Supersu.zip file from the root of your SD card.
Scroll to yes and install, after a successful flashing go back and reboot.
It is simple as that. You may download Root Checker from Play Store to verify your root privileges. After downloading, simply Install Root Checker, run it and you should get a success message after then.