Yes, you can already apply before you recieve your diploma. Due to the early application deadline, RSM normally uses the grades of the penultimate year (year before your final year) for the evaluation. This allows us to evaluate each applicant based on a full year of grades.
As you may have received fewer grades than normal due to the the COVID-19 pandemic, for the 2022 admission RSM will use the grades of your penultimate year and the grades obtained in the last year until December/January. Please note that it is not possible to submit grades after the 31 January deadline.