Yudda Kanda

This book describes the battle between the forces of Rama and Ravana. Having received Hanuman's report on Sita, Rama and Lakshmana proceed with their allies towards the shore of the southern sea. There they are joined by Ravana's renegade brother Vibhishana. The monkeys named "Naal" and "Neel" construct a floating bridge (known as Rama Setu) across the ocean, and the princes and their army cross over to Lanka. A lengthy battle ensues and Rama kills Ravana. Rama then installs Vibhishana on the throne of Lanka.

On meeting Sita, Rama asks her to undergo agni Pariksha (test of fire) to prove her purity, since she had stayed at the demon's palace. When Sita plunges into the sacrificial fire, Agni the lord of fire raises Sita, unharmed, to the throne, attesting to her purity. The episode of agni pariksha varies in the versions of Ramayana by Valmiki and Tulsidas. The above version is from Valmiki Ramayana. In Tulsidas's Ramacharitamanas Seeta was under the protection of Agni so it was neccesary to bring her out before reuniting with Rama. At the expiration of his term of exile, Rama returns to Ayodhya with Sita and Lakshmana, where the coronation is performed.