moogen,
No need must be with 2km. It depends on the no. of vacacny left and no. of kids register. If the kids register number is greater than the available places, then need ballot. The will separate into within 1km, 1-2km and out of 2m. If all apply is within 1km, so within 1km still need to ballot. If half half, then 1-2km need to ballot. If lots of places available no need to ballot.