Hi Prithwish093,
The AWA/Essay is a standard entity of the GMAT - meaning that you can respond to it in the same general way every time and consistently score at a high level; all you have to do is structure your essay in a specific fashion and stay on subject with whatever details are mentioned in the prompt. There are a number of different 'templates' that you might choose to follow (DisciplinedPrep linked to one in his post) - and you might find it worthwhile to read some sample essays (which are not hard to find). The Integrated Reasoning section involves a number of skills that you will learn while studying for parts of the Quant and Verbal sections (most notably CR with some RC and Arithmetic skills built-into certain prompts). Since many Business Schools don't place much (if any) emphasis on an applicant's IR Score, you might want to consider how much time you spend exclusively preparing for that section.
Before I can offer you any additional advice for your studies, it would help if you could provide a bit more information on how you've been studying and your goals:
Studies:
1) How long have you studied? How many hours do you typically study each week?
2) What study materials have you used so far?
3) On what dates did you take EACH of your CATs/mocks and how did you score on EACH (including the Quant and Verbal Scaled Scores for EACH)?
Goals:
4) What is your overall goal score?
5) When are you planning to take the GMAT?
6) When are you planning to apply to Business School and what Schools are you planning to apply to?
GMAT assassins aren't born, they're made,
Rich