There are a few different ways that you can check your GPU VRM temperature. The first way is to use a program like GPU-Z or HWMonitor. These programs will show you the current temperature of your GPU VRM, as well as other important information about your GPU.
Alternatively, you can also check your GPU VRM temperature by opening up your computer case and using a thermal camera to take a look at the VRM area. If you don't have a thermal camera, you can also just touch the area around the VRM to see how hot it is.
Finally, another way to check your GPU VRM temperature is to use a temperature probe that you can insert into the VRM area. This will give you a more accurate reading of the temperature, but it's a more invasive way of checking it.