Nilakantha sings the mantra: "Ambe Jagadambe", a Devi Kirtan. You can find this Kirtan in the Yoga Vidya Kirtan booklet under number 329:
Jagadambe Jay Jay Ma
Amba means divine mother. Jagadamba - Mother of the whole universe. Ma also means mother. Ma is the invocation of the divine Mother. Jaya means "victory", "triumph", "reverence", also "long live". And so there is said: "Homage to the Mother, homage to the Mother of the Universe...