Drivers are allowed on track at any point that there is time remaining in a session.
There is no requirement to wait to be allowed on track. iRacing’s software alone will determine when drivers are permitted / excluded from entering the track, and this may be influenced by time remaining in session, or if a driver has received a DQ due to failing to adhere to black flag rules.
FULL iRacing Sporting code rules, and rules within this rulebook are in place throughout practice and qualifying, including out laps and cool down laps.
This means that penalties can be assessed at any point during any session, including practice and qualifying.
Rules apply even when a session is completed / transitioning to the next session.