Extended: Tileset Collision Data

How do I retrieve the collision data from the tilesets?

I dont necessarily need all the collision data, just the tileset tiles that are collidable.

EDIT: Also…Is it better to do collisions according to tilesets (i.e. specific tiles on the tileset are collidable) or using tilemap (i.e. specific tiles on the tilemap are collidable regardless of the tileset reference)?

Any help would be appreciated.