Students need not take a Group 6 subject but substitute this for another subject from any Group.
Students may take 2 Group 1 languages and not a Group 2 language.
If students take Environmental Systems and Societies this is an Interdisciplinary Subject which counts for Group 3 and 4. Students can study ESS and have it count as either a Group 3 or a Group 4 course, or as both. If students choose the latter option, this leaves the opportunity to study an additional subject from any other group, including an additional group 3 or group 4 subject.
Please read through this IB Studies Guide and make your IB subject choices using the below form.