Need help 2011 Nissan Maxima AC was blowing a little warmer than normal. So, I added a can of Freon. It blew cold for about 3 to 4 weeks. Then while my wife was on her way home it started blow hot. I check the fuse under the hood on the driver side it was good. I then noticed the clutch was engaging. I tried finding the relay for the clutch. No luck. Could it be just the clutch gone bad.

The ECM on Nissan A/C's will prevent the compressor from operating if the refrigerant pressure is low. Since you know it had a small leak, maybe it turned into a bigger one. I'd check the system pressure before assuming anything about the clutch.

I was try to find the relay to check that first. But, can’t seem to locate it.

The relay is internal to the IPDM, it isn't serviceable. You can find the IPDM layout here on PG-61, the relay output to the clutch is a White wire on pin 48:
https://www.nicoclub.com/service-manual ... 0%2FPG.pdf

HOWEVER, it's only meaningful if it does go hot when you turn on the A/C. That tells you the clutch is bad. There are three other devices which can veto turn-on for various reasons, ECM, BCM, and A/C Auto Amp. So if it doesn't go hot, it probably doesn't mean you have a bad relay. It probably does mean something else is wrong in the system, like low pressure.