The AAT has the right to conduct a review on any decision that has been made and there various divisions that are relevant in providing a review for different areas. For example, the Migration and Refugee Division is in charge of the immigration area. It is the division that reviews decisions made by the Department of Immigration and Border Protection (DIBP).
An immigration agent from Sydney can ensure that you are preparing to meet the requirements for whatever type of visa that you are applying for. However, if it has been decided that your visa has been denied, there is something that can still be done to review this decision.
Every AAT review is supervised by a Member. A Member is someone who has been appointed by the Governor-General. The Member could be from a wide variety of backgrounds as it is not a requirement that they should be a lawyer.