I need more data from you in order to advise you. Use the below article to analyze your most recent MGMAT CAT:
http://www.manhattangmat.com/blog/index ... ice-tests/Then come back here and share your analysis. (Note: don't just share the data itself - tell us what you think it means. The ability to assess your performance is CRUCIAL to your ability to improve!)
Another note - you say you want to improve from about 650 to about 730 to 750 in roughly a month. That's a very ambitious plan - both because you're trying to improve 80 to 100 points (which typically takes longer) and because you want to reach a score in the mid-700s (which also generally takes longer - the higher you go, the harder it gets to keep going higher). You don't necessarily need to do anything right now, but I just want to alert you that you may need more than 4 weeks (the vast majority of people would) to get that kind of improvement.