Hi
Accountancy:TS grewal for numerical questions , Siddhiqui for clear concepts and great examples

business studies: Poonam gandhi and NCERT, also business awareness helps to value add so avid newspaper reading helps for case studies

Economics: Dr deepashree for micro and macro economics (2 separate books); also there is a combined book by Dr. V.K.Ohri and T.R.Jain (please dont refer to NCERT for economics)

Maths: first complete a chapter in RS Agarwal, understand the concept and then goto NCERT; RD SHARMA is more high level, NCERT + RS agarwal


Thank you::)