@Dnyanada
It really depends on the individual. I would say if you are a strong student, meaning that you have fairly solid verbal and quant skills then you can be ready in a month or so for the GMAT. I have seen students that have pulled off fairly solid GMAT scores in a month time frame, but then there is the large majority of students who spend two to three months to hit their target score. So the first thing I would do is to get a sense of your initial baseline.
And this is how I would go about doing it:
1) Buy the current
Official Guide to the GMAT 2015 book.
2) Review all the different types of questions that are part of the GMAT exam. Read the basic description in
the Official Guide.
3) Do first twenty questions from each of the sections in the GMAT: Reading Comprehension, Data Sufficiency, etc. This will give you a flavor for what the GMAT is about. The first 20 questions are the easiest and it is a good way to warm up.
4) After this take the free Official GMATPrep software. You can download it from here:
https://www.mba.com/global/store/downloa ... tware.aspx5) The GMATPrep full length CAT will be very difficult and you will have to be mentally tough to take it on. Do your best and try to finish each section, meaning complete all questions. There is a sever penalty for not completing the test. You may have to let go some of the hard questions.
6) The resulting score will be your initial baseline. Let's say your score a 620 in this test, then I would say it would be reasonable for you to hit a 700 in a month's time frame. That kind of an improvement is standard. Most students will score lower on their first full length CAT with minimal preparation, so please keep that in mind and don't be disheartened.
7) If you score a 500, then it will be more work and you will need a longer time frame, perhaps two to three months.
In summary, my advice would be to get a sense of where you currently stand and then make a decision based on that.
Cheers,
Dabral