Vanille-Noisette
I don't know when exactly they will send the final approval,normally my DOJ is on 15th of january and I received the final approval yerstarday but Im unemployed I just got my diploma,so I submit a query and I explain them that I am not working I am ready to join and at the same day I received the response that I don't have to upload the resignation letter.
I hope in your case they will send you the approval soon.
I absolutely understand that you have to be sure 100%,but you have to know that the Eticket and Evisa you will receive it one week before your DOJ and they will not upload your Eticket and Evisa if you didn't resign.
So my advice to you is to log in the portal and submit a query try to explain them your situation they are the only one who can tell you what you have to do.
Good luck