Corresponding With the Age and the Country Specific Regulations
It is a frequent object of discussions whether it is better to place the child in a grade corresponding with her/his age or with her real knowledge, and how to cope with possibly insufficient proficiency in the dominant language.
Although there is no perfect answer here, it is important to remember that the general situation is probably quite difficult and challenging for the child already, so all educational decisions in the first place should guarantee enough support for the child (linguistic, educational, psychological) and enough opportunities to integrate with peers, preferably not only other migrant peers, but also local students.