Q: cant get apple tv to show up on i tunes

The only reason for it to show up would be to restore if the device is connected via microUSB.

Does it need to be connected to power supply if its connected to macpro via micro USB?

You need to disconnect all cables, if you have a 3rd gen then you would reconnect power

http://support.apple.com/kb/HT4367?viewlocale=en_US&locale=en_US

its 2nd generation.  would all software updates be deleted with the factory restore?

Then it would just be the micro usb connected. It will load the latest firmware

I tried with several micro USB cables and still don't see it in iTunes?  Could it be that I have the 3rd generation and not knowing it! How could I confirm that is not a 3rd generation?

http://support.apple.com/kb/HT200008?viewlocale=en_US

Thanks for the link.  It appears that I have 3rd generation Apple TV.  Does this mean I have to connect it to my MacPro using microUSB and connect it to the power supply?

Yes.