Vikramjeet Ahlawat

First of all, try to learn about tenses. Then start reading novels and daily newspapers. The newspapers will be a bit challenging at first, but you will begin learning new words and buy a good dictionary for word meaning. Then start reading some literature books of class 10th and 9th that will provide you with a bit of knowledge about the old style of English. And try to speak English in front of the mirror so that you get a perception of how your English speech is and improve it.
Then you will start to understand fluent English like movies, t.v. Shows and always get subtitles so that you can understand the correct pronunciation of words in different accents.
 It will improve your English very fast and try to talk to someone in English at your home. That will give you confidence in speaking it more often.
 Good luck!

I am also an engineer, and many of my classmates went for GMAT and CAT. The thing you should be followings is the self-learning and an excellent preparation there are many coaching institutes but what matters is the self-study, and hard work for the specific exam but the format of GMAT and CAT is a little different. So if you have proper preparation, you will eventually land in the right college. For study abroad, they ask for work experience of 3 to 5 years, and if you have a good score in GMAT, you can go to your dream college.