Hi shashankverma188,
Raising a 530 to a 680+ will likely require at least another 3 months of consistent, guided study - and you'll have to make significant improvements to how you handle BOTH the Quant and Verbal sections. Thankfully, the GMAT is a consistent, predictable Exam, so you CAN train to score at a higher level. That having been said, the goal to raise your score 150+ points in just 1 month is likely too difficult to be considered realistic. This is meant to say that you might need to consider pushing back your Test Date and altering your application plans. Given your needs, you would likely find it beneficial to invest in a GMAT Course of some type (either Guided Self-Study or instructor-led), so you should plan to look into the available options.
I suspect that you might not be 'happy' with the idea of changing your timeline, but you have to remember your REAL Goal - to get into your first-choice School. There's no benefit to 'rushing in' an application if it's not going to be strong enough to earn you an invite to that Program. Beyond giving you the extra time to study for the GMAT, you will also be able to put more time into each individual application, meaning that you would likely benefit in a number of ways by giving yourself that extra time.
1) What are the next Round of application deadlines after Round 2 for each of these Schools?
2) Going forward, how many hours do you think you can consistently study each week?
GMAT assassins aren't born, they're made,
Rich