It's mixed bag of games requiring different sets of expectations. Six Siege is the easiest to run while Gears and Halo then increases in complexity. Warzone has it's own set of problems which you can search for, as in fps drops etc, that people have been experiencing after seasonal updates. Generally though, if you can get good performance in Gears 5 or Halo, since these two games in your list look to be quite up there in terms of system requirements, basing system specs on these two games should give you a good crack at Warzone.
Six Siege
https://www.techpowerup.com/review/msi-geforce-gtx-1660-super-gaming-x/22.html
Gears 5
https://www.techpowerup.com/review/gears-5-benchmark-test-performance-analysis/4.html
Halo Inf
https://www.techpowerup.com/review/halo-infinite-benchmark-test-performance/4.html
Couldn't find Warzone benchmarks and don't want to rely on YouTube because they can be unreliable and cant really compare to when the video was made and to the state of the game currently.
In saying all that, pretty much a system overhaul, cpu, mobo, ram and graphics card. Something that can get you close to 100fps in the games shown in the benchmarks above. Don't need to use same graphics presets so can lower it a bit to get more fps if you want.
Minimum core/thread cpu today would be 6/12. 12600k would be a good start. 16GB (personally would go 32gb off the bat to avoid mixing later as games start to use more) of either DDR 4 or 5, depending what board (ddr4 or 5) you go for. Up to you, search differences in performance vs price, Ddr4 is cheaper, 3600MHz is good speed.
Graphics card: 4series Rtx is nearing so you could wait to see what they offer and use 1060 as a placeholder until then. In the benchmarks above, you can see what level of gpu you would need so ill let you decide that.
Your psu will have to be renewed. If you want a powerful graphics card, i wouldn't look at anything less than 850w. Take note of power consumption of the card you want and the system specs the analysis is based on. If your rebuild is going to get you the fps numbers you want, as a majority, the system is obviously going to be beefy, so make sure the psu is tier 1 decent. There is a tier list in the psu section.