hai. 

these are the books that you can use for study purpose:

• The Perfect Study Resource for Delhi University (DU) BMS Entrance Test (Arihant Publishers)
• A Complete Self Study Guide BBA/BMS/BBM Entrance Examination (Arihant Publishers)
• Quantitative Aptitude by Arun Sharma
• NCERT books/Class 10+2 text books

even you can prepare online by refering sites and do previous years question papers as well.

if you feel certain topics are easy for you try to do all the difficult level questions and for difficult topics do some basic stuffs so that you can attempt easy aswell as medium level questions in examination. nothing can beat your hardwork. good luck for your examination.

thank you