First, I am using my Canon Camera 6Dmark2. I have a two flashes: one is the Godox V860IIC and a Canon Flash 600 EX-RT. I also have a wireless trigger Godox XProC. I can easily trigger the Godox Flash with my Godox trigger using channel 1 group A for the flash and having that set on the trigger. Now, the problemo is how to get the Canon flash to trigger as well! I can't seem to understand the manual for the Godox X2Tc and I thought I had to have this in order to get the canon flash to go off. Does anyone know how to do this?? I have been searching high and low on Google and Youtube and can't figure it out. Normally, I am pretty swift with technical material, this one eludes me. Thank you!
Your XPro-C and X2T-C Godox triggers speak a different "language" than the radio receiver in the Canon 600EX-RT flash. You can't control the 600EX-RT directly via radio with a Godox trigger.
To control the 600EX-RT with your Godox transmitters you need a compatible Godox receiver attached to the hot foot of the Canon flash. The only such receiver available is the X1R-C.
The X2T-C has a bluetooth receiver, but that is only for using select smartphones to control the X2T-C via the Godox app. It's not capable of acting as a receiver for other Godox triggers.
Be sure the channel numbers on the XPro-C and the V860II-C (or any X1R-C receiver you are using attached to another flash) match. All wireless ID numbers should also match.¹
¹ You may need to turn wireless ID to "off" on all devices to get things to work with the V860II-C, which does not appear to support wireless ID.
The 600EX-RT requires a Godox X1R-C receiver on its foot to work in the Godox X radio system. The X2T you purchased is a dedicated transmitter unit, like the XPro. The hotshoe on top is if you plan to use a non-Godox speedlight on-camera. stack a different system transmitter, or use an AD200 extension head on top of the X2T.
You could, of course, also switch out the Godox gear for RT-compatible gear instead, if you wanted to use the built-in Canon RT transceiver in the 600EX-RT. Aside from Canon's ST-E3-RT/ST-E3-RT v2, there are a number of 3rd-party transmitters, like the Jinbei TR-Q7/Westcott FJ-X2m, Yongnuo YN-E3-RT, and Phottix Laso that "speak" RT. As for RT-compatible 3rd-party speedlights, Jinbei makes the HD2-Pro/Westcott FJ80 and Caler 600EX-RT, while Yongnuo has the YN-600EX-RT and YN-600EX-RT II models. Keep in mind, however, that Yongnuo and Jinbei's RT systems do not work with each other, even though they both work with Canon's gear.
If you go with Jinbei/Westcott, there's the advantage that the speedlight and transmitter have a "Universal TTL" foot that can be used on any of the supported brands (Canon, Nikon, Sony, Fuji) for the Jinbei RT/Westcott FJ system. But the larger strobe choices are only the one speedlight and 200 Ws and 400 Ws li-ion powered TTL/HSS strobes and that's it (unless you're willing to go for older Jinbei RT/Adorama Orlit products).
If you go with Yongnuo, you are limiting yourself to Canon and speedlights only for future expansion.