I forgot to add the requirements that I officially got form IMAC:

NATIONALITY of CONTESTANTS
All contestants must either be a citizen of the country/nation they are representing, OR presently residing there. Passports or other ID (i.e. Residency status) may be required as proof by the Contest Director, or IMAC. Participants who have dual citizenship or residency status can represent either country, PROVIDING the participant has been approved by the model aviation governing body or the IMAC association in the country he/she is representing. A valid passport or other ID shall be required as proof in this instance of dual citizenship or residency.