Answers
On
Mary Tsiganou answered:
According to the European legislation, the member states shall issue a residence card to family members of a union citizen who are not nationals of a member state, provided that their period of stay exceeds three months. The deadline for submitting an application for a residence card may not be shorter than three months from the date of arrival.
On
Dimitris Foutsis answered:
You may invite them as relatives of Greek citizen. You should file an application at the immigration office.