Do you need students to sign up for a tutorial session?
Then Blackboard's self-enrol group sets are the answer.
What does a self-enrol group set do?
It allows a student to only add himself/herself to one group within the set - preventing him/her from enrolling in multiple groups - thus, choosing a tutorial session, for example, from the three available options)
Please join this training session if you are interested on learning how to set up self-enrol groups for students to sign up from.