At the end of Matrix Revolutions (Matrix 3), before the words "it is done", the Hindu mantra Navras is played. What context is Navras usually placed in? How do the Hindus view the mantra and how is it used, i.e. in ceremonial uses? Since Matrix universe is very much a mixed bag I do not think it has very much meaning in Matrix 3. Other than being a nice way of tying things together and to create a nice atmosphere.
I am a hindu myself, The mantra that u speak of is actually called "Navras" and not "Narvas". This song is from the Brhadaranyaka Upanishad, a philosophical text, with the famous shloka "Asatoma Sat gamaya" which in sanskrit means "Lead us from the unreal to the real". There is also a very elaborate translation by Swami Vivekananda on this upanishad which you should check out here - http://www.swami-krishnananda.org/brdup/brhad_intro.html.
P.S : The tune that is potrayed in the matrix credits is not how its used in traditional ceremonies.