Hello Perry,
"During the upgrade process there were conflicting VIB's that i had to remove. "
What exactly did you remove, why, when (e.g. before update and with a reboot after) and how?
"I did that and the upgrade was successful however, Now my nics are not showing up."
Did you test if these were functional after you removed some vibs but before updating? Don't forget that removing components that are loaded won't really apply until after reboot.
How did you update? If via the CLI did you use 'update' or 'install'? There is a big difference between these options, the former checks if you have a version of vib installed and if the one in the update package is higher it updates it, if it isn't there it won't install it. Conversely the 'install' option just blindly installs everything in the package - even if it is a lower version that currently present or wasn't installed already.
So it's likely going to come down to one of two things as the cause: 1. you don't have the required compatible driver installed or 2. your driver version/family has changed and is now no longer compatible with the firmware installed on the NIC.
First step would be to assess what is currently installed (driver+firmware) and cross-check these with the VMware HCL for these devices (don't just check 'BMC57xx' - get the specific part number and/or vendor IDs for the specific model of this device).
If you don't know what it was using before (that was functional), depending on the order of what you did before you may be able to just Shift+R at boot and roll-back to the last configuration (note that this doesn't remove your 6.5 install, just make no changes and Shift+R to revert back once more):
Do you have other hosts that are on the old 6.0 configuration and/or ones that are upgraded to 6.5 and see their NICs? If they are/were the same config then check what driver+firmware they are using.
Bob