Hi chhabramayank,
Studying for the GMAT now - far in advance of when you'll actually "need" your Score - is a smart choice. This gives you the opportunity to work with a variety of different study materials and find the one(s) that best help you to improve. 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 ones that best match your personality, timeline and budget.
In addition, since you're interested in one specific, highly-competitive School, you would likely find it beneficial to speak with an Admissions Expert about your overall profile and plans. Those Experts should be able to answer your Admissions questions and help define the specific areas of your profile that could use some improvement.
There's a Forum full of those Experts here:
https://gmatclub.com/forum/ask-admissio ... tants-124/If you have any additional questions, then just let me know.
GMAT assassins aren't born, they're made,
Rich