M.Tech

Please check for your eligibility to appear for UGC NET from the criteria mentioned at the link provided below. You will have to opt for engineering sciences as your subject in the NET exam. Regards.
https://www.shiksha.com/teaching-education/exams/ugc-net.

You have so much time for GATE exam. Even if you want to give it when you are in the 3rd year of your graduation then also you have 2 years. Download the syllabus of GATE for ECE students and start studying and for help join some online coaching like that of Ravindra Babu. It will provide you with the study material along with the necessary guidance.

M.Tech is a professional course, as in it is more application based, which includes understanding the techniques and technologies where as M.Sc is a basic course where you learn the fundamentals of an area.

No. M.Tech can only be done through students, who are from B.Tech background or have a M.Sc. Degree in Computer application. Moreover, I recommend you directly contact 18001024431, LPU - head office to know if something can be done for that.

There are over 103 Big Data & Analytics courses in India. Please refer to the link provided below for a detailed list of these courses and colleges which offer these courses. You should be able to navigate to the top colleges on this list using the filters on the web page. Regards. https://www.shiksha.com/it-software/big-data-analytics/colleges/colleges-india.

You have to write VITEEE exam to get the admission in VIT Vellore.
Additional Information: Predict engineering colleges you can get on the basis of your JEE Rank: https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor?utm_source=cconnect&utm_medium=CR_JEECP&utm_campaign=8321427.