IIM Ahmedabad - Indian Institute of Management Vastrapur Answered Questions

It is not something one can answer for you. It's something you need to discover for yourself. Rule of thumb: If you want to stick with the technical line then M.Tech. If you are more interested in management then MBA. Refer to this TOI article to make a more informed decision:
http://timesofindia.indiatimes.com/home/education/news/MBA-vs-MTech/articleshow/21908011.cms

The selection process of all the IIMs is a two-stage process. The first stage is a shortlist based on your CAT score(CAT or the Common Admission Test is an exam conducted by IIM's every year for admission to various courses. CAT scores are used by all the IIM's and many non-IIM's as well) and your academic scores(class 10, 12, under graduation, post graduation etc. Different IIM's set different proportions of CAT score and academic scores to shortlist candidates for the next stage). The next and the final stage consists of Group Discussions and/or Essay Writing tests accompanied by a personal interview. The final selection is made by combining the scores obtained in CAT and the individual components in stage 2.

Sorry to inform you this but your BE score will definitely play a spoil sport for admission to IIM A, no matter how high you score in CAT percentile terms. Having said that, I would suggest you to prepare one more year meticulously, to aim for FMS which does not consider previous academics while selecting candidates for admission.

Prepare well for CAT. Hard work is the only way to get a decent percentile in CAT. I would suggest you to join a coaching center and religiously follow their guidelines if you are not self motivated enough. Otherwise, get your basics right and then go for mocks for practice.