Authors note:

(Qi Condensation Stage)

[1>9]

(Qi Refiner Stage)

[1>9]

(Foundation Establishment stage)

[ 1>9]

(Core Formation Stage)

[low >mid >high]

(Nancent Soul Stage)

[low >mid >high]

(Soul Formation Realm)

[low >mid >high]

(Dao Seed Realm)

[1>10]

(Dao Tree Realm)

[1>10]

(Void Traveler Realm)

[1>10]

The first 3 realms are considered trainee desciples.

The mid 3 realms are considered independent cultivators.

The last known 3 realm are known as Peak of Dao cultivators.

There will be higher realms above Void Traveler but you'll have to wait and see as the story progress.