Planning for group 2 and 2 papers in group 1

Now you are having 90 days for 6 papers. 90 days are sufficient if you know what to study and how to study.

Coming to the first questions i.e. what to study refer followong books for exam preparation they are exam oriented and can be prepared in short period of time and can provide magic results - 

FR - Refer your existing material (No change)

Audit - Pankaj Garg book + His Scanner (Change if you are not confident with the existing books)

(Give more focus on these 2 subjects FR + Audit and least pass first group in the next attempt)

AMA - This is very lenghy subject and requres lots of practice. Join classes or do self study but clear all doubts (take help from friends, online lactures etc.)

ISCA - Manish Valechha textbook is widely recommened. Use with PM (No need to refer SM) This book is very well written & contains memory codes which help you to remember the contents easily.

DT - T N Manoharan with Vinod Gupta summary module. Prepare self notes for lengthy topics for revision.

IDT - Vineet Sodhani is best. It can be prepared easily.

Addressing second question i.e. how to study - Since you have secured 2 exemption in 40 days, i can assume that you know how to study different material. Use your existing study method. Dont waste your time. Start Now. Try to give more revisions in order to improve the accuracy and presentation, it will help you to secure more marks.No one can tell you how to plan things, You will have to DO IT YOURSELF. Start your study as soon as possible without wasting much time.

All the best :)