Can I charge AirPods Pro with Apple Watch 6 disk charger?

Hello,

No, the cable that comes Apple Watch Series 6 has the disk on the end and can't be used.

However, any matching adapter and cable (with a lightning connector) from a previous or current iPhone can be used.

If you decide that you need to purchase a charging adapter for use with your AirPods, get one similar to this:

20W USB-C Power Adapter - iPhone Accessories 

Good luck.