I can understand your problem, I think you can try admission for your son in Kendriya vidyalaya school. There fees is very reasonable if you can afford. Even there you can try for RTE also where your son will have education free of cost. But at what standard you son is studying, because Kendriya vidyalaya always do the admission for the first standard only. If your son is now going for the first I think you can give a try even if the admissions are closed. I hope my suggestion may help you.