Requirements for the rooting:
==>You need a laptop/PC with better enabled internet connection.
==>SP Flash tool. Download here
==>Of course i always point out your patience in following.
How To Root Tecno Boom J5
==>You will need to download and save superSu.zip to your smart phone’s SD card
==>Another download will be for the ported TWRP specifically meant for your Tecno boom J5 device, Get it here
==> Now next is to Unzip the TWRP zip file and accurately flash the recovery image to your smart phone device tecno boom j5, using the Sp flash tool.
How To Flash it by Using SP Flashtool
Please Check the guide/steps here
==> Now in TWRP Recovery, select the install Zip the one from your SDcard, note, for you to select or choose zip in your SDcard use the volume up and down to go up and also to scroll down, now select the Supersu.zip file from SDcard where you have root. Scroll to where you see yes and install it, now go back and reboot after a successful flashing.
My friend after the above steps followed, have it that your smart device Tecno Boom J5 is now successfully rooted and to be sure of that download Root Checker here
Root Checker helps you to know/confirm/verify if you phone is successfully rooted.