Here I giving you some preparation tips for MBA entrance examination for admission in reputed colleges in India below :

You should start preparation start as soon as possible.
First of all you must know complete syllabus and exam pattern of MBA entrance examination. You must give at least 12 to 14 hours per day for studies..

Then you have to give more attention for important topics of quantities aptitude and reasoning for MBA entrance examination. You can also join coaching classes for MBA entrance examination.
For better preparation you have to solve the previous year question paper of MBA entrance examination or you can buy books for it
You have to make notes for important topics of MBA entrance examination and revised them regularly.

Best books for MBA entrance exams are :
Quant Aptitude by Tata Magraw Hill , Author:Arun Sharma
Nishit Sinha's DI LR book by Pearson
Quantitative Aptitude for MBA Entrance Exams by Guha Abhijit
A Communicative Grammar of English By: Geoffrey Leech