Hello NK123,
if you were born outside cyprus, my understanding (now we are in the EU) is you don't need to do army for as long as you don't have cyprus citizenship.
Once you apply for citizenship (ne real benefits) you will need to do army. The last i heard it is now 3 months (possibly changed from 6)
Depending on the type of job you do, you may need citizenship to practice (eg, being an architect, doctor and so on).
These are the rules so far, you can live in cyprus as long as you want without the fear of conscription. I have an exit visa, i now never show it and it never gets asked for!!
hope this helps.
Pantheman