No problem. If you pass the ATSAT and are selected for hire, you will be given a TOL. Last year there was some speculation that they found those who were close to 31 and got them TOL's in time, but I can't promise that's true.
I met quite a few older guys while I was at the academy....they were able to sneak some 30 year olds but I don't specifically remember any 31 year olds.
One other thing is last year they were giving out "Pre TOLs". I got one in June, but have no idea if that locked in my age or if it was the full TOL in October.