Good question, priyotech. :) That is a good starting point - and, actually, I could use even more information.
Mahesh, please let us know what you have done so far and what materials you have available. Are you studying on your own or have you been taking a class / working with friends / using a tutor?
I'd also like to get some more detailed data on your strengths and weaknesses in order. Use the below to analyze your MGMAT CAT:
http://www.manhattangmat.com/blog/index ... ice-tests/Then come back here and tell us the results of your analysis. (Note: do share an analysis with us, not just the raw data. Part of getting better is developing your ability to analyze your results - figure out what they mean and what you think you should do about them!)
Also, you mention that your goal score is 720+ and you have about 6 weeks until your exam date. A 120+ point improvement in 6 weeks is an ambitious goal - most people would need more time. If you are not locked into a particular deadline, you may want to keep in mind that it's possible you will need to postpone your test date. (I'm not saying you definitely will have to do so - you'll just have to see how things go.)
I also recommend reading this:
http://www.manhattangmat.com/blog/index ... -the-gmat/Make sure to follow the links to the other articles within that article.