Sthayi

Sthayi or Asthaayi is an initial phrase or line of a fixed, melodic composition in Hindustani music. It's a way of systematizing the parts of a composition. The Sthayi part of a Dhrupad is the first of four stanzas and uses the middle octave's first tetrachord and the lower octave notes.
Sthayi means an octave. Shadjam to NIshadham is called sthayi or an octave. It is called a position. Basically there are 3 stayis but 5 stayis are correct too. 
Anumandra sthayi, mandra sthayi, madhya sthayi, tara sthayi and athithara sthayi.