If there is no corresponding cyanogenmod rom for my Samsung Galaxy On5, how do I install Cyanogenmod? My phone is rooted and I have the TWRP installed. I am not sure where to go from here though.
There are likely sources to build CyanogenMod from scratch. I did find the forums at xda  helpful http://forum.xda-developers.com/t/samsung-galaxy-on5 I wouldn't be suprised if you see CM 13 or 14 in the near future. If you are on a linux box you could possibly build from scratch.