You should prepare well to crack MBA entrance exams.

Various common national level tests to get into the finest B-Schools of India are:

CAT
XAT
SNAP
JMET
MH-CET
CMAT

Various individual tests of some other finest B-Schools of India are:

IBSAT
IRMA
NMAT
MICA
IIFT

XAT is somewhat easier than other exams

But with XAT, you can approach only Xavier institute of Management, Jamshedpur..
With CAT score, you can approach any B-SCHOOLS in India.
CAT is the toughest exam

Lists of exam along with exam date:

Exam Exam Date
Common Admission Test (CAT)
1 day test window in November

Xavier Aptitude Test (XAT)
First Sunday of January

Indian Institute of Foreign Trade (IIFT)
Third Sunday of November

Common Management Aptitude Test (CMAT)
5 day window in last week of January

Management Aptitude Test (MAT)
First and second week of February
First and second week of May
First and second week of September
First and second week of December

NMAT by GMAC
One and half months window from first week of October to third week of December

Symbiosis National Aptitude Test (SNAP)
Second Sunday of December

Maharashtra Common Entrance Test (MAH CET)
Third week of March

Tamil Nadu Common Entrance Test (TANCET)
Fourth week of March

Integrated Common Entrance Test (ICET)
Fourth week of May