If you want to see the status of the students you have invited for a tournament, you can see that in the”Players” tab.
There are the following 3 status types:
If the student has accepted your invitation and joined the tournament, his/her status will be “Joined“. It will be “Invited” otherwise.
And the status will be ‘Exited’ if the player has exited the tournament. You can find more details about players joining a tournament late and exiting here – LINK