From Rigpa Wiki
1) The genuine Akanishtha of the space of phenomena is the place where all buddhas reside; hence, no place is above this pure land.
2) The symbolic Akanishtha of inseparable wisdom and phenomena appears in the shape and color of a celestial palace. This is the abode of the sambhogakaya; so it symbolizes the pure land of the space of phenomena, for which nothing is higher.
3) The awareness Akanishtha is the wisdom awareness that realizes the fundamental nature of things just as they are. This is the abode of the dharmakaya of twofold purity, so there is no higher awareness than this pure land.
4) The secret Akanishtha is the secret place of the consort. Given that this is the abode of the secret kaya, nothing is higher than this path, its place, and its noble qualities.
5) The conceptual Akanishtha is the beginner's visualization of the palace. This is the abode of the surpassing samadhi mandala; hence, based on the generic image, there is nothing higher than this understanding.
6) The worldly place of the Akanishtha is one of the five pure abodes of the gods. This is the abode of all sublime ones; so within the realms of form, there is nothing higher.