Deploying a Red Hat Linux Enterprise 7 x64 virtual machine on ESXi 5.1update3.
The “Red Hat Linux Enterprise 7 x64” OS options is not available in the drop down list when trying to deploy a new VM from the vSphere client.
Just to confirm, it is supported in ESXi 5.1 update 3 (others might say update 2). (See VMware compatibility guide http://www.vmware.com/resources/compatibility/search.php?deviceCategory=software&testConfig=16 )
However, to deploy with the option to select Red Hat Linux Enterprise 7 x64 for the OS, you will need to deploy from the web client and not the usual vSphere client.
Just tested with web client with SSO an the VM deployed successfully.
Useful 5.5 article https://communities.vmware.com/message/2401557