The Oral Assessment takes place at the same time and place as the Simulation Lab Assessment, so you don't need to register for it separately. The focus of the Oral Assessment is to evaluate your ability to make clinical decisions, and to think critically in a health care setting. The oral assessment takes about 10 minutes, and involves the assessor asking you three questions that may be related to the case you've just completed during the SLA, or a case that involves a similar context. The assessor will also hand you the questions in writing so you can read the question at any point during those three minutes. As they did during the SLA, the assessor will be scoring your responses as you go along.
Take a look at these resources to help you prepare for this oral assessment.