Are "Saya Asadharana Nana" part of Nibbana?
Yes, the Buddha attained each of these knowledges at the moment of enlightenment.

No, the knowledges are mundane, and thus sankhata (formed). They are a by-product of the Buddha's specific enlightenment, not qualities of nibbana itself, which has only three qualities, viz. voidness, signlessness, and desirelessness.