You can follow below strategies to prepare for GATE exam-

1- You should make your proper plan regarding it. So, that you can easily do your preparation along with your engineering.

2- You should follow GATE syllabus.

• Refer to GATE Syllabus 2018 for Electronics and Communication Engineering section-wise, as given below.

• Section 1- Engineering Mathematics

• Section 2- Networks, Signals and Systems

• Section 3- Electronic Devices

• Section 4- Analog Circuits

• Section 5- Digital Circuits

• Section 6- Control Systems

  Recommended

• Section 7- Communications

• Section 8- Electromagnetics

3- Analyze previous year papers to understand the exam pattern and level of questions.

To check the recommended books for your preparation you can refer below link

GATE Preparation

This is very good to know that you are so serious about your Gate preparation but as per my view it is better to start your preparation in your 3rd year because first 2 years of B.Tech is the ideal time to make all your basics concept clear and strong. Apart from this, below I am providing Gate preparation tips which you should keep in your mind whenever you start your preparation  -
1. Know the syllabus very well.
2. Read standard books only as there are many books available in the market so it is advisable to use the books which make all your concepts clear and which are easy to understand.
3. Understand the weightage of topics properly.
4. Proper Revision plan should be followed.
5. Mock Tests and Practice Tests should be done as this will help you to learn time management skills and this will also make you familiar with the exam pattern.

Hope this helps!!!