I came across two stories on how Ravana was killed by Rama but not sure which one is correct.
Story 1 : Rama used Brahmastra to kill Ravana. Brahmastra was so powerful that it killed Ravana instantly and his body was burnt without even leaving ashes.
Story 2 : Ravana wanted to be immortal. However, Brahma gave him the nectar of immortality which resided in Ravana's navel. It was then Vibhishana who told Rama the secret to Ravana's life which was held in his navel. Rama then dried up the amrit which resided in Ravana's navel. This is even shown in the popular Ramanand Sagar's Ramayana. I do know that Ravana asked Brahma that he can be killed either by Manav & Vanar because Ravana never considered them powerful enough to kill him. I am not sure about story of Brahma giving nectar of immortality to Ravana.
I have also read that Ravana's body was still there and Vibhishana performed the funeral rites.
I think that the above line can be true in case of story 2 not story 1.
Moreover, there is another story that Ravana gave some valuable lessons to Laxmana before dying.
I have been trying to dig out the truth from different sources but they have confused me as I came across different stories. Can anyone help me to know the real story on how Ravana was killed?