Hi jain95vasu,
When it comes to studying for the GMAT, there are a variety of different options. From what you describe, an online Program that would allow you the flexibility to study at your own pace (and when your schedule allows it) would likely make the most sense. Most GMAT Companies offer some type of free materials (practice problems, Trial Accounts, videos, etc.) that you can use to 'test out' a product before you buy it. We have a variety of those resources at our website (
www.empowergmat.com). I suggest that you take advantage of all of them then choose the one that best matches your personality, timeline and budget.
If you have any additional questions, then you can feel free to contact me directly.
GMAT assassins aren't born, they're made,
Rich