i didnt attend GMAT, but had written KMAT which is called Karnataka MAT..which is a state oriented exam for colleges in Karnataka.

Coming to preparation u may be going through 3 steps usually...written, GD and an interview type. U need to qualify all the three. But for me it was only written and GD was conducted by the college.

U just need to be aware of all the current trends of business, read business journals and go through all famous newspaper....BEst of luck