Complex sentence: The Senior Secondary Division of the school has students who opt for Science (both pure and applied), Commerce and those who aspire for IITJEE, AIEEE and national level competitive exams.
Split into simpler sentences: The Senior Secondary Division of the school consists of students who opt for Science (both pure and applied) and Commerce. Many of these students also aspire for IITJEE, AIEEE and national level competitive exams.