The most important essay on which your success depends is the one in which you write about your reason for pursuing an MBA once again. Use the optional essay or the career essay to address this issue.
Articulate a convincing argument in favor of your decision to apply for an MBA again. The reason is likely to deal with gaps in your experience and knowledge to pursue a shift in career goals. The new career goals are likely to have developed as a result of an experience you had some time after your first MBA. You are likely to have discovered new personal traits or skills which you would like to put to use while pursuing your new career plans. Or, you were exposed to a new business opportunity which you would like to pursue because you consider yourself a natural fit with the requirements for success in the opportunity.
It is very important to show that you have already taken some steps in direction of your new goals. On the concreteness of these steps would depend how convincing your argument sounds.
You should also address that there will be duplication of courses when you pursue the program once again. But the unique experience of the school you are applying to should more than compensate for this. Also write how you can make the most of the common core courses by laying down specific personal-experience-based learning objectives for each such course. Of course, your experience and previous learning will make your contributions useful for others in the class.
Here is a list of business schools that accept International applicants for a second MBA.
Other Indian applicant issues