You can loop through the x and y width and height of the tilemap and compare if they are overlapped.
for x in (tilemap.width / tilesize)
for y in tilemap.height/ tilesize)
tilemap.tileat(x, y) is overlapping sprite -> do actions
But with your example picture you are going to have to draw the colission box of that circle as an oval, if you are intending for the center part to count as "not touching"
another approach might be to draw the circle as a series of small sprites if you run into issues