It is not recommended to do so. However, you can easily check for the type of tile via the tileMap node:
tile_pos = world_to_map(pos) #Maybe you don't even need this
tile_type = get_cell(tile_pos.x, tile_pos.y)
You can either get the position of the needed tile by iteration or by your mouse cursor or character position. The get_cell(...) method returns the Tile ID as an integer number. Each tile has a different ID.
Hope this helped!