Is my twelfth-grade score of 90% (or 99.5% in intermediate) sufficient for eligibility in Ireland?

Yes, your 12th-grade score of 90% (or 99.5% in intermediate) is generally sufficient for undergraduate admission to universities in Ireland.

Irish universities typically look for strong academic performance in secondary education. Some programs or universities may set higher requirements or have additional subject criteria, especially for competitive courses.

With your excellent academic record, you are well-positioned to apply.