I know that the 'Om Namah Shivaya' mantra is present in Krishna YajurVeda, but i have been led to believe that it's also present in the Shukla YajurVeda. Please share the location the verse.
In the famous rudra ashtadhyAyi of MAdhyandina samhita. There is this mantra in the fifth chapter. It is taken from the moola samhita.