TonT
Six means Six.
If after Six, you have a problem trying to reapply, simply get a new email address and use that.
As long as you study, be positive and smile, you'll be fine.
Make sure you google everything and anything about Qatar Airways espes fleet size, aircraft orders, new routes and future routes. Also, have a good look at the Qatar Airways website for news. When they ask you what do you know about Qatar Airways, make sure you know as much as possible. It will show you have taken the time to do your homework.
Good luck