Assuming you have the TUF board and a 13th gen K/KF-series CPU, there are no 4 DIMM configs for DDR5-6400 on the TUF GAMING Z790-PLUS WIFI Memory QVL
. The "socket support" column must be "1,2,4" for a 4 DIMM config; if it is "1,2", that's a 2 DIMM config. The fastest 4 DIMM config on the current QVL for that board and a 13K CPU is DDR5-6000, but that's for 4x16GB; the fastest 4x32GB config on the QVL for a 13K CPU on that board is DDR5-5200. If you have a 12th gen or non-K CPU, there are no 4 DIMM configs on the QVL.
That doesn't mean that you absolutely won't be able to get it to work; it might work with some effort. 4 DIMM configs are harder to get stable than 2 DIMM configs. I suggest trying some speeds between 4800 and 6400, as people have reported some success with 4 DIMM configs and overclocking a bit below the advertised XMP overclock speed. N.B. you need to run a long memory stress test to be certain that it's stable; it's possible to have memory overclocks that can boot but cause crashes later, if they are just a little too fast.
I'd start with trying it at 5600 with the XMP timings, see if that's stable.
In general, you can't have the fastest memory speed and the highest capacity simultaneously. Bigger DIMMs (i.e. 32GB) are harder to overclock than smaller ones, and combining that with a 4 DIMM config is even harder. Note also that combining multiple kits of memory is another thing that can be problematic or add to the difficulty; even if they are identical part numbers.
Lastly, you might find some improvement by updating your BIOS (update the Intel ME (Management Engine) and ME driver first).