Secondary School Assessment - Help (Abu Dhabi)

We plan to move to Abu Dhabi in August and have been informed that our 16 year old son needs to complete an assessment as as possible to gain entry into a secondary school.

Given the time of year, all schools in Ireland are currently closed and August would be too late to do the assessment in the new school.

Anybody know a solution to our problem or have any ideas?

We only recently got confirmation of the job offer and it's all very last minute.