First off, you can order and download the TWRP, ADB/fastboot tool as well as the root zip from here: http://www.saroms.co.za/product/mobicel-r9-plus-twrp-custom-recovery-helps-with-root/
NB. Before you proceed, please note that for successfully completion, the process involves userdata wiping. So you want to either take a back up first or shelf the project for the time where you should either be able to backup or not mind loosing all your data.
- First, copy the root zip file to your Mobicel R9 Plus' internal memory.
- Copy the adb/fastboot folder (which also contains the recovery.img file) to drive C:
- And then again from your Mobicel R9 PLUS interface, enable Developer Options by repeatendly tapping on Built number under Settings > About phone - from there enable "OEM Unlocking" as well "USB Debugging"
- Reboot your Mobicel R9 Plus to Recovery mode
- Then select "Reboot to bootloader" and connect the device to the PC via
- Open your ADB/Fastboot folder and launch the fastboot tool (comment below if you need help with this)
- Command: fastboot oem unlock (this will wipe your Mobicel R9 Plus' data)
- Command: fastboot flash unlock
- Command: fastboot flash recovery recovery.img
- Command: fastboot reboot
- Reboot to recovery (TWRP recovery it should be now)
- Agin wipe userdata first from the TWRP menu and "Wipe"
- Navigate to 'Install' > Install zip > nav to the root zip placed on step 1
- Install it and reboot to system when done
- At this stage you should be rooted as well
Post any question you may have in the comment section below and I should glasdly clarify further