Complex sentence: It would appear that at the request of Kutsa who was the son of one Rajarishi called "Ruru", Indra helped in decimating Ruru's enemies and invited Kutsa to Indraloka to celebrate the victory.
Split into simpler sentences: It would appear that at the request of Kutsa (who was the son of one Rajarishi named "Ruru"), Indra helped in decimating Ruru's enemies. Indra invited Kutsa to Indraloka to celebrate the victory.