When should I buy books?

i think you should purchase atleast before 6 month of exam.......................

and the whole course is not changed ....................rather just only 2or3 topics are changed..................

you can manage it ..................................

for DT-IDT-LAW, you should compulsorily go with relevant amendments and they are available on www.icai.org.................

Finally , you can find all the amendments on icai.org site..................