for group 2 u can follow the following books:
Costing - Padhukas or Vashist & saxena
MICS - ICAI module & dinesh madan
DT - TN Manoharan or Padhukas
IDT - Bangar or vaitheeswaran or padhukas
in IDT vaitheeswaran notes are very simple and lucid and other two that is padhukas & bangar are
Q & A type.
normally all padhukas are Q & A type only.
the above books mentioned are only few there are some others books available in the market.
ALL THE BEST FOR YOUR EXAMS