here. Apparently, no list survives (see here) so it has to be reconstructed, e.g., see here.
How Do We Get Nine?
2 primordial opposites, cold and heat, Niflheim and Muspelheim;
2 kinds of gods, Aesir in Asgard, Vanir in Vanaheim;
2 kinds of elves, light and dark;
2 other kinds of beings, men in Midgard, giants in Utgard/Jotunheim;
But Hel might be part of Niflheim. Dark elves and dwarfs may or may not be identical. One name for the world of the dark elves is Myrkheim (see here; see also Mirkheim.)
At the Ragnarok:
the giants, the dead from Hel (led by Loki), Fenris Wolf, the World Serpent and Muspel will attack Asgard;
former inhabitants of Midgard will fight on both sides (we do, don't we?);
elves will remain neutral (?);
Vanaheim will survive and some of the gods will return from it later.