R4L/Services/Hosting/Advanced/PHP.ini
From R4L Help Wiki
In order to override global php.ini settings under your hosting account, just create a file named .user.ini anywhere under your public_html directory (or sub-folders below this) to override some global php directives.
e.g.
max_input_vars = 6000 memory_limit = 128M upload_max_filesize = 128M