You need to provide more information for someone to suggest anything concrete. Some starting points can be-did you analyze the test well? If yes, which area in Verbal did you do well on and which area was the worst ? How long have you prepared for and how exactly did you prepare for Verbal ? Do you understand the the concepts and question types well or is it that you struggle with the application of concepts inspite of knowing the concepts?

It is also possible that you would actually need to work on your test taking skills. More often than not,we tend underperform on timed tests so taking a few more will help you improve your time management and test taking skills.

Not able to analyze the test as link for review is not visible. Probably, I pressed some wrong button.
Problems I personally know are: 1. Very low accuracy in CR at High difficulty level and consume more time(>2min) while solving CR.
2. In SC I know the concepts but in timed conditions it becomes difficult to put that all together.
3. In RC I am comfortable enjoy high accuracy even in High difficulty range, but in timed conditions accuracy falls.
I was preparing for past 2 months by solving OG13 and analyzing all the choices in every question for theory I studied MGMAT SC, Kaplan 800. I usually study 15hrs a week, though I can put 6hrs/week more.

Experts plz advise.

You know, this isn't all that uncommon - the clock and the test-day pressure definitely play a pretty big role in almost everyone's performance. A few things you can do to help counteract this on your next test:

1) Take practice tests. It sounds like you feel comfortable with the content and strategy but need to simulate those timed conditions and the overall stamina of taking the test in one fell swoop. Your study to this point will help, but for "putting it all together" you should really get to work under test-like conditions.

2) Practice the verbal section while tired. One thing a lot of people underestimate is how much of a toll that whole test day takes on your ability to focus on the verbal section, which comes last. If you were acing SC and CR questions and focusing on (and enjoying) RC passages when you did verbal practice after sleeping in on a Sunday morning, now it's time to make sure you do some math review before you start verbal or you do verbal homework at the end of a long workday. This will force you to use strategy to stay focused and attentive.

3) Check whether you're too reliant on note-taking for RC and CR. If you're taking too many notes, that's labor-intensive and can make the clock a factor and weigh on your stamina a little bit. See if you can do a verbal practice test and use 2/3 as much scratch paper as you usually do.

Thanks, Brian for nice inputs. "Practice while tired" seems nice idea. I have started taking short quizzes(20-25Q)from Verbal Review," Line of Thinking" in timed condition is different from that in un-timed conditions.

I don't take notes at all for RC &CR and if I encounter a long passage then I will take notes , but I believe that end product of reading a passage should be a good comprehension.