Which son of Ravana was killed by Hanuman?

The son of Ravana killed by Hanuman was Akshayakumara.

Akshayakumara, also called Aksha or Aksha Kumara, was one of Ravana’s sons and a young warrior of Lanka. After Hanuman entered Lanka while searching for Sita and devastated parts of the Ashoka grove, Ravana sent Akshayakumara to stop him. The prince confronted Hanuman in a fierce battle, using weapons and fighting from a chariot.

Although Akshayakumara displayed considerable courage and skill, Hanuman ultimately killed him. The episode appears in the Sundara Kanda, the portion of the Ramayana centered on Hanuman’s journey to Lanka. Ravana then sent Indrajit, also known as Meghanada, who managed to restrain Hanuman with the Brahmastra.

A common mix-up is confusing Akshayakumara with Indrajit because both are Ravana’s sons and both confront Hanuman during the Lanka episode. Indrajit is not killed by Hanuman; he is later killed by Lakshmana in the wider war. Kumbhakarna is Ravana’s brother, not his son, while Atikaya is another son who is killed by Lakshmana.