Who can taste the Nectar?

According to the Gurbani, he alone can drink the Nectar who dies while living or in other words, becomes dead (unattached) to the world while still living in it.

They who are dead to their self and so alive, taste the Nectar; their mind through the Guru's Word is attuned to the Lord's Love.

Asa M4, 447-5

Our outer senses have free play while the subtle and causal senses are dormant. When the soul puts an end to the activities of the outer senses and travels within to the subtle and spiritual regions, it is called the state of dying while living.

If the soul leaves the nine doors and becomes concentrated at the tenth door behind the eyes, it can then drink the Nectar.