You probably need to ask on the mod page for w/e multiplayer mod you are using.

Originally posted by Chudwick:

if i have all the dlc's and host a game so my frens can join, do they need all the dlc too? or do i have to trim it all to base version? i couldnt find anything on this. thank you

What Beef Hammer said, but generally, yes.
The DLC is treated as mods, and its likely you will experience desync galore, if they can even connect in the first please. Check in the mod page/mods discussion.

I have played a fair number of Rimworld Multiplayer over the years (2 people), and none of them have been flawless experiences (even with no mods), so best of luck to you.