Uttara Kanda — The last book, Uttara Kand, describes the birth of Lava and Kusha to Sita, their coronation to the throne of Ayodhya, and Rama’s final departure from the world.
Epilogue – It has description of banishment of Sita, birth of Luva and Kusha, sons of Rama and Sita, and Rama’s departure from the earth to Vaikunth, the abode of Lord Vishnu. The fifth adhyaya of the Uttar Kanda, describes a conversation between Lord Rama and his brother, Lakshmana, and is usually referred to as the Rama Gita, it is essentially an Advaitic philosophical work.
The Uttara Kanda concerns the final years of Rama, Sita, and Rama’s brothers. After being crowned king, many years passed pleasantly with Sita. However, despite the agni pariksha (fire ordeal) of Sita, rumors about her purity are spreading among the populace of Ayodhya. Rama yields to public opinion and banishes Sita to the forest, where the sage Valmiki provides shelter in his ashrama (hermitage). Here she gives birth to twin boys, Lava and Kusha, who became pupils of Valmiki and are brought up in ignorance of their identity.
Valmiki composes the Ramayana and teaches Lava and Kusha to sing it. Later, Rama holds a ceremony during Ashwamedha yagna, which the sage Valmiki, with Lava and Kusha, attends. Lava and Kusha sing the Ramayana in the presence of Rama and his vast audience. When Lava and Kusha recite about Sita’s exile, Rama becomes grievous, and Valmiki produces Sita. Sita calls upon the Earth, her mother, to receive her and as the ground opens, she vanishes into it. Rama then learns that Lava and Kusha are his children. Later a messenger from the Gods appears and informs Rama that the mission of his incarnation was over. Rama returns to his celestial abode. The Uttara Kanda is regarded to be a later addition to the original story by Valmiki.