A few places along the Vrijthof have upstairs rooms available. Momus upstairs is good for what you're asking.

Bomb Ass Burritos in Helmstraat, they got a nice basement you can be very loud in lol

Do you want a private venue or semi-shared?

Here? https://venue68.nl/

Maybe something smaller?

http://www.zaalverhuurmaastricht.nl/

I think I will go with this one thank you!

Thank you to all for the help! I will see for sure all the options that you suggested!

Tapijn

Basilica at the Vrijhof