This is how I understand Nibbana.
Nibbana is a state of unconditioned which means that there is no cause and effect taking place and thus after parinibbana will not be in this world as this world of 31 planes of existence still belongs to the conditioned world with cause and effect.
Nibbana is also called vimokkha which has 3 form of liberations through the comtemplation/understanding of Tilakkhana (anicca, dukkha, anatta) and they are: 1. by understanding anicca gives the conditionless (or signless) liberation (animitta-vimokkha), 2. by understanding dukkha gives the desireless liberation (apanihita-vimokkha), 3. by understanding anatta gives the emptiness (or voidless) liberation (suññatā-vimokkha).