Question 3 intake fans and 3 or 2 exhaust??? XPG Valor Mesh

I'd try 2 front intakes and a single exhaust at the back as a starting point. That would be standard.

Change that if disappointed.

But you have 6 fans and may insist on using them all for reasons other than cooling. Some like spinning machinery and lights.

Or you may be willing to experiment for hours and hours to reduce temps by 3 degrees rather than saying "that's good enough". Depends on how fearful you are about temps. Some worry a lot more than others.
 
What kind of CPU cooler are you using?

If it's a tower cooler then you definitely don't want two exhaust on the top. In this case 3 intake, 2 exhaust (back and top back) would likely be the best configuration.

If it's a downdraft cooler like the stock AMD and Intel ones then I'd suggest trying both the config mentioned above and with 2 exhaust in the top and one at the back. Normally I'd say just go with 3 intake/3 exhaust, but that case seems awfully small depth wise so I'm not totally sure about having intake and exhaust right next to each other like that as it may cause excess turbulence.