I have a VM that is running Windows server 2012 and its licensed, the question is If i delete the VM will my license be lost? or i can use it again on a new VM?
same thing for RedHat VM
If it's a Windows 2012 Standard edition license, I believe it would be ok to re-use the license unless you are not assigning the license to a new VM more than once every 90 days. So if you build a virtualized cluster and are vMotioning or Live Migrating VMs (each licensed with individual copies of Windows Server Standard) around (manually or by DRS) then you need to make sure that the server has the appropriate number of licenses assigned to it prior to the workload running on it. In other words, it must be licesed for the max number of physical procs of a host available in the cluster.
So the proper version of the Windows 2012 to implement in VMware environment is Windows 2012 Datacenter that you will need to get license per physical processors and then you can have unlimited instances of Windows 2012 VMs implemented in your VMware SDDC.
Windows licenses can be uses as the below in a virualized environment:
You can get more info from the Microsoft Windows Lic in Virulized environment document below: