When the department of Immigration refuses your visa application that you had applied for while in Australia (onshore), you will be provided with an opportunity to have the decision reviewed at the Migration Review Tribunal (MRT). Migration Review tribunals (now called the AAT) offers an opportunity for those whose visas have been refused to present their case once again but without making the same mistakes as the previous time. This is essentially another chance for you as the previous decision by the immigration department will not be taken into consideration while reviewing the merits of the case. The decision will be based on the evidence presented to the tribunal.
However, the applicants get only one chance for this. Further review of the AAT decision can be made by the courts. However, it is important to note that the courts cannot review the merits of the case. They just determine if a mistake was made in the process of refusal or cancellation.
It is thus very vital to make the best use of this one off opportunity. You may not be able to afford any mistakes with the application. With experience in the field, we can assist you with your MRT review in the best possible manner.