SB 12.7.15
manvantaram manur deva
manu-putrah suresvarah
rsayo ’msavataras ca
hareh sad-vidham ucyate
Translation:
In each reign of Manu, six types of personalities appear as manifestations of Lord Hari: the ruling Manu, the chief demigods, the sons of Manu, Indra, the great sages and the partial incarnations of the Supreme Personality of Godhead.