That would be yes, but no.
Yes, NRaas Traveler has an option to remove the block on teens registering for Uni. I've sent many teens to Uni for a "head start" that way, usually but not always with older siblings or cousins. When the term is over they still have to finish high school back home. IRL we would call that an Advanced Placement (AP) program. ;)
If they still cannot register for Uni by phone or computer, with the mod we can travel them there as if on vacation and once arrived register them for a new term at the Admin Building.
No, we cannot push a sim out to Uni or any other world and not play them. The way Uni World works is that active play is on that world only while any of our sims are there and the homeworld is frozen in suspended animation with time not moving forward until the term is over and active play returns there -- same as the WA or any other destination worlds. The game engine is only capable of simulating one world at a time.
Using Traveler we can switch a sim or household's homeworld on them and leave them there, but they won't progress at all while not being played. This doesn't really apply to Uni World though, you can't leave sims there and expect them to do anything in your absence. The Uni term would become broken if this were attempted.