GMAT

Hi Jayesh,
You can find a list of coaching centers here-
https://testprep.shiksha.com/ielts-exams-coaching-classes-in-ahmedabad-categorypage-14-51-930-0-0-30-109-2-0-none-1-0
https://testprep.shiksha.com/gmat-exams-coaching-classes-in-ahmedabad-categorypage-14-51-928-0-0-30-109-2-0-none-1-0#cateSearchBlock
Hope it helped.

For executive program there is a minimum work experience cutoff of 5 years. Once you complete 5 years you can apply for executive program at IIMs.

GMAT scores are valid for five years only.

Dear Vipul,
3rd year of b.com is best time for appearing for GMAT reason being if you appear at early stage and manage to score good but still you won't be getting admission till you complete graduation and by the time score validity will be expired.so it is advisable to appear for in final year after exams.
All the very best

Hi Vipul,
Though you must device your own strategy you may read this
http://www.mba.com/global/the-gmat-exam/prepare-for-the-gmat-exam/test-prep-materials/the-gmat-prep-timeline.aspx
Hope it helps. Good Luck.

above 250 score is to possible it

Hi Arjun!
I have taken the GMAT and scored a 760. Here is my debrief in which I have mentioned how I prepared and the study materials I used - http://learningroots.in/gmat/gmat-debrief-760/
Generally, an aspirant requires 3 months on an average to crack the GMAT. A score of 700+ is generally considered a good score.
Feel free to ping me in case of any queries.

Hi, GMAT preparation requires a dedicated study plan. You must know which areas you are good and weak in. Take mock tests and you will know your current position. You can then prepare accordingly. It is best if you take help of a coaching center.

Hi Vipul,
This portal does not allow us to endorse or advertise any external organization. It is entirely up to an individual if he wants to take coaching or not. Take mock tests, if the scores are really low and you feel you require additional help take help of a coaching center. You must prepare a study plan and stick to it for better results.

GMAT is required for MBA admission. First, you need to meet the other eligibility criteria. If all is good, you can get exemption also.