Hi & Welcome to Linux Questions.-
RHEL is a server class operating system for the enterprise
and it is a 'paid for subscription' through Red Hat.
Are you sure that you want to pay for an os?
May I suggest to run CentOS which is the rebuild/free version of RHEL.
Since ISO2USB didn't work for you I'd give UNetbootin a try. Or try Rufus:-
Other members may have other suggestions.
You may also want to include system information and specifications about your computers architecture so others know what they are working with in order to help you.*-::-