This is determined by many factors, such as driving experience, seat time, driving education, attitude, car type and modifications, number of tracks visited. But experience in enhanced, safety-oriented, high-performance driving (HPD) schools, or racing schools, is the primary contributing factor. Here is an example table you might use to gauge your approximate level.

Note, this is not cumulative. I.e. after you've take 2 events at novice level, you may move up to the intermediate. Then after an additional 4 events, you may graduate to the advanced level.

Examine the learning curve graph below, representing a general rate at which many drivers progress. Note the days scale is not real-time: it is the accumulated track days. Also note that in general a driver progresses quickly after their first couple of events but then progress to higher levels takes longer periods of time...

All that said, the final decision lies with the organizers.

Also, you should remember that sometimes drivers are placed in different levels not by their ability but by the remaining space in a sold-out school.