Need help with Randomly Sorting people based on preferences

Hi there,

I am new at this forum, so I am not sure if I'm posting this in the right place. I have a group of people that need to randomly sorted bases on their preferences.
This time there are 68 persons and they have to state 3 preferences (they can choose out of 5 courses) and will be placed in 1 course. In each group there is only place for 12 persons.
This time there are 2 groups (2 x 12) of AZG and 1 group of the other courses (MZG, KJ, GGZ, EGT). It is possible that the people are not able to be placed in a group, so they will be in the leftover group.
So the people should be placed in a group by order of preference if possible.

I have tried several things but and I know how to randomly sort by 1 preference but not with more preferences and a max on groups etc. Any thoughts?