Well, you know what happens to NCERT or Govt. books in schools. Students prepare from guides/keys etc. available in the market. Same is true for IEI books. They are not helpful in passing AMIE exams. Reasons are multifold. These books are not based on exam trend, do not include previous year problems, are static, no online support, no objective type questions and what not.
These books can help in one area - to help you study a subject many times and afterwards appearing in a subject twicw or thrice!
Go for good coaching material to save time. Try study material by AMIE(I) Study Circle.