The number of nadis, or subtle energy channels within the human body varies in different schools. The idea of 3 nadis, which correspond to 3 pillars or columns, represent a minimal configuration. At the upper end there is discussion of 72,000 nadis.
The Nadis in India have a Chinese equivalent in the idea of Meridians which also serve as the basis of Chinese and Japanese acupuncture.
Nadi is also 150th part of the ascendant in a birth chart based on the sidereal zodiac. Such a birth chart is called Rashi Kundali. It is impossible to cast accurate charts without knowing which nadi rules a person or time. Each nadi has an aspect of the devi ruling it, and a solar and lunar part -- hence there are 3600 in the zodiac.