If you visa application is successful you will be issued with a pre visa which has conditions. The visa officer will request Confirmation of Enrolment (COE) letter, evidence of payment of Overseas Students Health Cover (OSHC) and any further documents mentioned in the conditions for pre visa such as Medical examination.
C1Group will help you through this process. C1Group will forward your payment to your educational institution and obtain COE and OSHC documents and forward it to your visa officer along with your passport and other documents mentioned in the condition. Your Medical report will directly be forwarded to you visa officer.
Once all your documents are received student visa is just a formality.