Nyas Meaning

Nyas means establishment. It means establishment of your own desired God within your desired body organ accompanied by chanting of mantras. This is done to relax out the tired out body or any specific organ and to fill it with new energy. Nyas is an important method to remove dosh (inefficiency) of our body. Nyas is an important spiritual method in Hinduism to reactivate human emotions and to re-establish lost energy among different organs, of lost joy in various unliving beings too. It is often done before starting of any good work.
Practicing Nyas has been since Vedic times and is fore runner of Reiki.

Source : http://en.wikipedia.org/wiki/Nyas