Train from Dusseldorf to Paris

​@ezbethk 

Where do you search? Don’t use the Rail Planner app to plan your trip, use instead an official site, e.g. bahn.de or sbb.ch:

You can find a reservations guide here:

https://www.seat61.com/interrail-and-eurail-reservations.htm

​@ezbethk 

A correction of my previous post, it is possible that this train is already sold out for passholders. I will search other possibilities.

So would I book these tickets through eurail?

​@ezbethk I provided a link to a reservations guide in my first answer, you will find the best options to book the reservations (I suppose that you have already an Interrail/Eurail Pass). I found a second connection from Düsseldorf to Paris: 

You can book the TGV or ICE reservation between Karlsruhe and Paris from raileurope (they dont charge a booking fee on top of the reservation cost) 

Also:

The ICEs going from Germany to Paris are in my opinion more comfortable then the TGVs on that route.