I am running Custom Lenovo image of ESXi 6.0.0 update 2. Can I patch using standard VMware patches with update manager or do I need updates that are specifically for Lenovo customized image?
If you're updating with standard VMware Patch, just VMware packages (vib files) will be updated. To ensure the custom parts from Lenovo are updated too, one must add the specific depot, like the HPE one (vibsdepot.hpe.com) or add the offline bundle (just assuming this could be found in the driver section of Lenovo website).
hope this helps
After scanning the hosts against your baseline, you can see how many, and which components are going to be updated prior to applying the patches. This way you can check whether any of the Lenovo provided/replaced components are affected.
I'm not sure about Lenovo, but other major vendors like HPE, usually provide an OEM package for each "Update xx" version, and support patching this version, until a new "Update" version is released.