Srimad Bhagavatam Canto 12, Chapter 07, Text 15

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.
Srimad Bhagavatam Canto 12, Chapter 07, Text 14
Srimad Bhagavatam Canto 12, Chapter 07, Text 16