Raahil:

A common fix is the following:

Within Nuendo press F4. You will see your VST conneections. Under the default stereo output you will see a column labeled "click." Next to the assigned physical outputs column, left click to make sure "click" is turned on in that column. Assuming your physical connectivity is correct, you should hear the metronome.

Please let me know if this works. Thanks for supporting Steinberg.