The manufacturer's name and model number are often stamped into the underside of the tile. Call them up or search their web site.

There are two ratings you need to know: Static and Rolling Loads.

You should also take a look at the slab below. If you are in a multistory building and not on grade then you also need to be concerned with the capacity of the floor slab itself. The pedestals concentrate the load an dcrfeate a punching load. This will require a Structural Engineer (PE).