Introduction
Virochana is the son of Prahlada and the father of Bali (Mahabali). Genealogically he is a minor figure in the Puranic king-lists, but he appears independently in the Chandogya Upanishad as a seeker of the truth about the self.
Family
In the Chandogya Upanishad
In a well-known passage of the Chandogya Upanishad, both Indra, for the gods, and Virochana, for the Asuras, go to the creator Prajapati to learn about the self (atman). Prajapati first teaches that the self is simply the reflected image one sees, for example in water. Virochana, satisfied with this, returns to the Asuras and teaches them that the body itself, adorned and cared for, is the self, which the text presents as the basis of the Asuras' outlook. Indra, unlike Virochana, returns to question this answer further, and eventually receives a deeper teaching.
In the Puranic genealogy
In the Vishnu and Bhagavata Puranas, Virochana is simply named as Prahlada's son and Bali's father, without an independent story of his own beyond this Upanishadic episode.