I understand your problem it is hard to crack IPMAT BMS BFIA like course for that you need good institute and a good book but my friend it not compelet true. you may also prepare some online class it is cheap and provides all fundament study material which you may need to pass an exam So they are good and cheap also help to get a better score. 

all the best.

I can recommend you the holy grail at least for the Indian competitive exam scenario book for quantitative aptitude. R. S. Aggarwal. Complete the relevant exercises which is in your course, and repeat them again. And then, practice from which ever material you can get your hands on to. 

You can purchase delhi university bms guide, in my views that book is the best to prepare yourself for bms entrance exam. i am personlay offering you to purchase that book. this book will be available to you online on amazon and flipkart.

Hope you find it helpful

let me know in the comment box if you are having any further doubts

thanks

Good Luck!