Parents any advice please. school enrollment problem?

my son is has special needs and i really want him starting school in september. Iv spoke to the school i want him going to and met with the principal who told me its my choice for this sept and to bring al relevant reports down to him which i did yesterday (left them with the secretary). i was brought over to speak with the resource teacher who strongly advised me to hold him off till next september but also told me again it was up to me. I told her its this september im going with. Now this moring i get a phone call from secretary telling me principal wants to discuss my sons enrollment. Im finding all this very daunting has anyone any ideas as to why he wants to see me??? might I add this is a mainstream school with some resources but may have to get on to the department for more help.