Saptak means "gamut" or "the series of seven notes".
It denotes the set of swaras i.e. Shadja (Sa), Rishabha (Ri), Gāndhāra (Ga), Madhyama (Ma), Panchama (Pa), Dhaivat (Dha), Nishada (Ni), Shadja (Sa) which comprise a musical scale in Indian classical music.
The usual scale of Indian music spans from Sa in the Madhya Saptak to Sa in the higher, Taar Saptak.
[1][verification needed] Generally, a raga involves notes from three saptaks.
Considering the Sa of the Madhya Saptak, the frequencies of the other svaras would be, 2.