Which subjects require coaching for ipcc?

I have recently cleared CPT with a score of 166/200.
I have registered for the IPCC course.
I was wondering whether I should get coaching for all the subjects.
Or can the theoretical subjects(Tax, Law etc) be studied without any coaching?
I don't want to take any chances, so is it possible to do well in theoretical subjects without classes or are there some tricky areas that require help.
I'd appreciate it if my seniors would clear my doubts regarding this.