I had my HU(Avic6200) installed but cant seem to get the camera view option to work just black screen and says objects may appear reversed..It comes on when I put truck in reverse....

Vehicle 2013 Silverado 1500

Did you confirm that the camera is powered?  your symptoms indicate that the headunit is working as expected  but the camera isn't powered and therefore you have a black video feed.

Can you test the power to the camera with a volt meter and confirm there is power going to it?

Also if you think it's not a camera problem doulbe check that you have the correct imput.  It's easy to mix up with some of the others and have the RCA plug in the wrong port.

I had the exact same issue and the problem was the back up camera connector had pulled out of the back of the head unit as I was stuffing it back into the dash.  Because you're getting the "objects may appear reversed" message, your HU definitely knows that you are in reverse.  Most likely, that means the backup camera is getting power, because the circuit that tells the HU you are in reverse is the same one that powers the camera.  Hope that helps. 

I had my HU(Avic6200) installed

Most likely when your installer wired the head unit, they wired it so it's powered from the 12v reverse signal wire.  So the camera only has power when the truck is in reverse.  It's not your installers fault, most documents including metra say to wire it this way. 

When i installed my HU, i wired camera power from the 12v ignition wire.  So the camera always has power when the car is on.