Most universities require a band score of 6 to 7 depending on the university and type of degree or postgraduate diploma.  If you intend to study at an overseas university you should take the Academic module of IELTS.  Most university prospectuses will state what IELTS level they require and you may even find that some universities will lower their requirements if they have places remaining on their courses.

If you intend to study in an overseas high school you can take the General Training module which features simplified reading sections.