Help creating a route for sub-folder holding controllers

which version of codeigniter are you using? if you are using codeigniter 2 then use this, it allows you to use subfolders in the controller 

https://degreesofzero.com/article/contro...niter.html

you just create the file, drop it in, and thats it, works perfectly. 
if its CI 3, or if above solution does not work for CI 2, try adding index to the route
$route['admin'] = '/admin/home/index';