Mac Mini (late 2012) running El Cap (10.11.6) host with 16 GB RAM

1. You can download the Mac OS X El Capitan on Virtualbox on Windows by accessing the link below. Also, make sure that you have enough back up before you proceed with the same. There are a lot of duplicate ISO images on the market and it is best to download the same from a trusted source.
2. Os X 10.11 El Capitan Retail.vmdk Virtualbox. This is a virtual machine with Ubuntu 14.04.1 LTS and ROS Indigo Igloo pre-installed. It is packaged in an.ova file that you can run on VirtualBox or other virtualization engines. A usable, scripted, up-to-date installation procedure for ROS on (a bare) OSX Yosemite or El Capitan.

Install Mac OS X El Capitan on VirtualBox. Before going to install Mac OS X El Capitan, you need to download VirtualBox. After that, you downloaded successfully VirtualBox install the software on your PC. Remember one thing that VirtualBox and VMware Workstation this too is one of the greatest tool Virtualization.

Download Mac Os X El Capitan Virtualbox

VirtualBox 5.2.8
Trying to install El Cap as guest using
Selecting In Wizard either Mac OS X (64 bit) or Mac OSX 10.11 El Capitan (64 bit) gives same end result
Assign 4 GB RAM
Create Virtual Hard disk - VDI Dynamically 49 GB
System settings ICH9 - enable I/O APC - enable EFI - Hardware Clock in UTC
Processor 1 CPU - Execution Cap 100% - enable PAE/NX
Paravirtualization interface is default - Hardware virtualization enable nested paging
Display 128 MB - 1 monitor - scale factor 100%
All other settings default
Start VM and select 'Install OS X El Capitan.dmg' from the menu.
Booting starts.
Pauses after ApplFSCompressionTypeZlib load succeeded.
Sometimes it stayes there forever (well longer than I can wait!) and sometimesz it goes on to
Missing Bluetooth Controller.

El Capitan Vmdk

Another pause then screen turns to garbage with 'no enrtry' sign (circle with slash through it)

Macos El Capitan Iso Virtualbox

How can I get it to work?
Thanks!