It should be playable by any civ if there were no rule changes to the map. Since none of the standard map sizes are set to 24 civs, if you want to play with all of them at once you will have to explicitly set the number of players. To do this, open the map with the editor and go to the "Scenario Properties" window where you can set that. If the map had pre-defined start locations for less than 24 civs, you may want to either add extra locations or delete the ones that were there so that they get assigned randomly.
If there *were* rule changes to the old map, then what you want to do is open up the PTW editor, select "Import" from the file menu, check the map option, and then select the BIC file of the old map. This will ensure you play with standard PTW rules. You can then save this scenario with a new name to a .bix file, although you will still have to set the number of players to 24 if that is your wish.