On another forum I frequent (non-religious, but with a religion section), a woman with a lower elementary aged child asked about which church to take her child, since he was showing an interest in Jesus and God. This was a household where Christianity isn't really practiced, more New Age-type stuff. Someone else who has attended Orthodox parishes, but is not Orthodox, suggested the mother take her son to an Orthodox parish since we go lighter on the hell and damnation thing - and that the boy might find friends and others to support him if he decides to be baptized. The mother doesn't believe Jesus is God, but her son is interested in Jesus and God, and she wants to support him.
I had to add my two cents that looking for an English-language parish might be a good thing, given the circumstances.
I also added that it might be a difficult thing for just such a young child to become Orthodox - and that now has me thinking - I can't even imagine a 6 yo converting to Orthodoxy himself without either parent being Orthodox and not even believing Christians. Orthodoxy is so much more a whole life than just going to church on Sunday, even for a young child. In addition, a child in such a family would pretty much only be "Sunday Orthodox" since I suspect getting to other services would be near impossible.
That doesn't even take into account that I really wonder if a priest would baptize a child in such a family.