Is this for personal cad use or professional commercial usage? 5-6K for a proper autocad system is rather low as you need a workstation level PC especially if your doing 3D cad, rendering, and simulation with others ie Solidworks.

I'd recommend getting:
Core i7 class with at least 8 cores, 12700, 12700K or 13700K
Peerless Assassin or Frost Commander cooler
Pro grade mobo so either MSI Pro B660M-A or Z690-A
32/64GB 2666MHZ RAM. You want it to run at JEDEC speed rather than XMP for system stability
2/4TB NVME SSD. CAD files, especially 3D eats storage space
Any of the more recent Quadro family GPU. An equivalent to RTX 3060 would do fine. These are for professional type usage as in your requirement
800+ W Gold or Platinum grade PSU. Go for A tier for ultimate stability
Any well ventilated case if you are going to use it 8hr a day
Win10/11 PRO or Business license if you going to use it as a business

It would be something similar to myway1985 suggestion if you plan to build your own.