Manipura chakra is the seat of the fire within the body. Located at the navel, this is the chakra of the life force.
According to the Shiva Samhita, one who contemplates Manipura chakra not only conquers disease and death but also acquires the ability to enter another body.
Amrit kup in his nabhi, naval may also be result of his yogic powers. Through his penance his Chakras were well developed, making the lower 5 much stronger.
When Ram's arrow was pearced through his nabhi, the vital force giving him strength, stopped. Resulting in his soul leaving his body later on.
He didnt die immediately. His soul was in the 4th Anahat chakra.
5th, Vishudhhi chakra, the throat chakra, controls speach.
When it reached 6th Agya chakra, he gave knowldge to Lakshman. 6th, Agya chakra stores a lot from past, present. He gave that knowledge to Lakshman.
After that his soul reached Sahastrar chakra, the 7th one.
One whose soul leaves from Sahastrar, merges with Divine. That was Ravan's Mukti.