Thanks for prompt reply.
I had installed oracle VM Virtual box on 32 bit hardware system.
Based on you suggestion I have installed oracle VM Virtualbox on the hardware with 64 bit and OS Windows 8.1 64 bit.
I have completed SAS University Edition import with guest operating system version "Red Hat (64-bit)" as default selection while making new virtual machine.
When I updated an option "Share Folders" under "Setting", guest version changes to "Unbuntu (32-bit)", and I did not see 64 bit guests as an option any more.
I need help so that I can see 64 bit guests as options under "Setting > General > Basic > Version".
Right now I can see all version of Linux 32 bit only.
For more detail please open attached file.