The GMAT (Graduate Management Admission Test) is a 3½-hour standardized exam designed to predict how test takers will perform academically in MBA (Masters in Business Administration) programs. GMAT scores are used by graduate business schools to make admission decisions. It is basically used if you wish to enroll in a university abroad i.e in some other country.

It is not at all compulsory if you wish to enroll in an MBA college in India.
For MBA in India there are number of tests which you can give like CAT, XAT etc.

choose where you wish to go and then go for the respective exam.

Hello,

GMAT scores or any other entrance examination scores helps you to get admission into good Colleges. It is not necessary to give a GMAT or CAT for getting Admission into a medium College depending on the College. Some of the colleges also offers their own Entrance tests. But, it becomes Better if you appear for entrance exams like CAT or GMAT because it increases your chances of getting Admission into good Colleges and is considered as minimum requirement to get Admission into some of the Colleges.