I have a small VMWare environment for VDI. I have 2 esxi 5.1 hosts, vcenter 5.0, and View 5.1. I would like to get vcenter upgraded to vcenter 6, which I have a spare license for, but I am assuming I would then have to upgrade everything else and no one knows the license info for our view connection server. This is an environment that I inherited, so I have had to do a ton of digging to find anything. I have looked everywhere to try to find the account for my View license but have had no luck. Could I get away with NOT upgrading View if I upgrade to vcenter 6?
The short answer is no. Its not compatible. You need to be at view 6.1 for esxi 6.0.0 or view 6.2.3 which supports 6.0U3.
VMware Product Interoperability Matrices
This happens a lot at small companies as the last IT person or the IT person before the last IT person put a license in their personal email or their own name. I would call your VMware rep they should be able to do a search for all licenses under your companies email domain, then you can redirect that email to your own account and find out what is happening with your licenses. I always encourage people to put that stuff in to a generic email address so it doesn't end up in the wind.