my son was also born in dec02
he's in k2 now and will go to p1 in 2008
(government requires children to be at least 5yrs 8mths when they take p1)
as your son has repeated in nursury and is now in k1, i assume you'll let him take k2 and k3, so he'll join those born in 2003 and go to p1 in 2009
ie.
2006-7 k1
2007-8 k2
2008-9 k3
2009sep p1