Hello, this is a vCloud Networking & Security (vCNS) sub-forum.
Do you have a vCNS in your isolated network?
To connect one of your RHEL VM to the Internet, you would need a device/host that connect to the Internet and probably do a NAT for your RHEL VMs.
You can use a firewall, proxy, router, server or a VM based firewall/router such as vCNS, NSX, or a linux router/firewall
Bayu Wibowo | VCIX6-DCV/NV
Author of VMware NSX Cookbook http://bit.ly/NSXCookbook
https://github.com/bayupw/PowerNSX-Scripts
https://nz.linkedin.com/in/bayupw | twitter @bayupw