Your faculty notifies you, usually by email (it can also show as a hold on the student portal). Apply online through the readmissions link on the student service portal, explain your grounds and upload supporting documents. The Faculty Appeals Committee looks at your overall record, your letter of motivation and your documents, and an incomplete file can stop a decision. The deadline is in your faculty letter. If the appeal fails you can ask the Senate Review Committee on Readmission to review it, but it checks whether the right procedure was followed, not the academic decision itself. Source: up.ac.za academic exclusions page.