Thanks guys for the help here is my problem

I have a commercial tenant who handled the build out of his space with his own contractor and is responsible for it. He complained about a roof leak that it was damaging a ceiling tile causing it to break and he had to keep replacing it. When I took a look I realized it wasn’t a roof leak but condensation from the air duct that is going through the middle of the tile. There is a standard 7x12 or what ever size grill that is screwed into the tile itself not the boot. Is that even legal? To top it off the duct is not properly supported and all its weight was being supported by the ceiling tile that has a big square cut in it. The tenant now has the boot resting on wooden 1x4’s that are sitting of the drop ceiling grid so there is a gap of 2 or 3 inches from the bottom of the boot to the tile. Clearly a few things are wrong here but my main question is can you even use a grill like that or does and grill need to be a specific one for drop ceilings. I am going to go look at the rest of the my spaces in a few minutes to see but I 90% they all have the standard 24 inchx24 inch grills you see in commercial spaces