The PHP v5.6.x was removed due because this version is not anymore supported.
All sites was updated to PHP7.x
You can choose your version for your site inside your cpanel client area.
Also, cPanel services will stop using PHP 5.6 and move to PHP 7.2 in WHM version 76.
Our present version is the 74.0.9 release stable
Sunday, October 14, 2018