Complex sentence: There are no compulsory subjects in year 13 and students can choose any 6 subjects, however taking Study (code 13SDY) is highly encouraged for most students, as 6 full subjects is demanding, and is considered overwhelming for all but top students.
Split into simpler sentences: There are no compulsory subjects in year 13 and you can choose any 6 subjects. But taking Study (13SDY) is highly encouraged for most students, as 6 full subjects is demanding, and is considered too overwhelming for all but top students.