To verify if the vGPU unlock worked, type this command
mdevctl types
The output will be similar to this
0000:01:00.0
nvidia-256
Available instances: 24
Device API: vfio-pci
Name: GRID RTX6000-1Q
Description: num_heads=4, frl_config=60, framebuffer=1024M, max_resolution=5120x2880, max_instance=24
nvidia-257
Available instances: 12
Device API: vfio-pci
Name: GRID RTX6000-2Q
Description: num_heads=4, frl_config=60, framebuffer=2048M, max_resolution=7680x4320, max_instance=12
nvidia-258
Available instances: 8
Device API: vfio-pci
Name: GRID RTX6000-3Q
Description: num_heads=4, frl_config=60, framebuffer=3072M, max_resolution=7680x4320, max_instance=8
---SNIP---
If this command doesn't return any output, vGPU unlock isn't working.