6 subjects can be a lot to juggle in one year, in my opinion.
This year I am doing Methods, Chem, Biol, English and Revs. Even with only 5 subjects, I have struggled with schoolwork, let alone had a life outside of VCE+extra-curricular activities.
Humanities subjects can be quite troublesome. Learning the content will require a lot of time and copious amounts of memorization, especially for the history subjects. In addition, a lot of hard work for one subject will not necessarily translate into a good study score. Humanities exams tend to be a bit more risky than their science/maths counterparts. If you haven't prepared for a specific question, deducing the answer on the spot through logic isn't generally an option.
On the positive side though, many of the key skills such as writing essays and analysis of documents are shared between your subjects. Studying for one subject may perhaps indirectly help you for your other subjects.
In the end, all I can really say is choose any option that's right for you. Think it through. Have a look now at how much work needs to be done for each subject. Make a plan and just go for it.
Good luck for next year
