Understand Coaching isn't important:It is not a tough exam to crack. You just need to be consistent with your study during engineering. A period of intensive study set in during the last three to four weeks prior to the exam and taking a series of mock tests to gauge your performance could make you better competitor. If you have a good understanding of the subject, coaching not required.
Practicing problems, making concepts crystal clear and going through the last 10 years' question papers is essential. Memorizing formula will not be helpful as problems are not straightforward. So, focus on practice.
To prepare well for GATE, start preparing yourself well for the semester exams as well. Study concepts carefully and clear your doubts as you study the course. If one has studied well in every semester, then two to three months of preparation will be enough.
Create a book of concepts for different subjects and read one or two standard books for every subject. This way you'll find yourself more confident. And, start creating this book from today.