If you have a particular house in mind, go to the property & look for a notice on a window or the front door, if there is one there, it should have the information for who the house is being assigned to, which REO agent.
If there is no notice yet, you really just have to wait until the bank's asset manager assigns it to an agent. If you were to just call the bank they won't be able to help you, they'll just say something like "that property hasn't been assigned yet".
The other answer here is correct: The commission is set by the bank & it's not going to be any less whether or not you have your own representation. It's best to have an agent working for you. It doesn't cost you anything.
You won't be able to inspect the interior either until the House is assigned to an REO agent.