Promothesh
1. Your Application is a whole. When you are applying across great distances, you need to tell the Adcomm why they should take you. Well look at it from their standpoint. Why will they take you ? There can be many reasons or a combination
a) Your academic records are stellar. You have been an outstanding student, attended India's best university, great grades. You also have a great research experience and have done some notable things like publishing till now
b) You have a very high GMAT score
c) You have written a Great statement of purpose and it is very clear why you will be an outstanding research candidate
d)You have glowing recommendations from people who are doing cutting edge research in marketing area
hmm. got that ? It may be that for a couple of candidates , it is absolutely clear case and the adcomm may not even have to think before offering them admission. But in 90% of cases, it is not clear. Then , What is the differentiator ? A great GMAT ? MAYBE !!. It may also be SOP and recommendations. So , to answer your question, if you do not have ANY OTHER differentiator, make GMAT your differentiator. Otherwise, what is the USP ?
2. You need to start communication with profs/PhD students whose research interest you. I don't know about marketing, but I am sure you can continue the dialogue. You may not get response easily -since a prof will be only interested in responding to you if he/she sees that you will add to his/her "intellectual capital". So you need to go thru some research areas, identify some areas, develop your own ideas and then talk !
Does this help ?
Linda has posted link to a good page on her site. I am not canvassing for
accepted.com but this page provides some good pointers to Indian students applying for MBA. Some hints are good also for Phd.
https://www.accepted.com/mba/indianapp.aspx