You can start your preparation but I would suggest you to focus more on Your Graduation first. Here are some important tips you can follow.

1 . Know your GATE 2018 Syllabus, Exam Pattern thoroughly

GATE has two types of questions –

• Multiple Choice questions (MCQs): These questions have options and candidates must choose carefully as there is negative marking for these questions

• Numerical Answer Type (NAT) questions: These questions have to be calculated and carry no negative marking.

2 . Know the Weightage of Topics in GATE

3. Make your Study Plan for GATE

Remember the points

• Check the past year papers and exam analysis.

• Divide the Topics broadly into Strong, Weak and to be read properly.

• Keep daily, weekly and monthly targets. Try to adhere to them as far as possible.

• Next schedule your preparation such that you revise the easy ones along with the tough ones and the “never read before” ones. This will ensure you have a clear view of what is to be studied and how you are going to do it.

• While many advise to check the weightage and study accordingly, it is really not the correct way to go. Check the weightage by all means and understand the important topics but don’t neglect to study the not so important topics

• Make Short Notes while you study as this is will be helpful during revision.

• Write down Formulae that you find difficult to remember so that they are handy for revision.

• Don’t wait for completing a portion of the syllabus. Start practising with test papers as soon as you done with a section or topic. Little steps of water make the mighty ocean.

• Keep the solved problems separately indexed so that you can refresh and revise later when required.

• Another tip for final year students is that you can match the topics that you will be studying in your graduation and club the studying part so you cover these to get a better hold on them

4. Also Focus on Engineering Mathematics and General Aptitude

5. Strengthen your concepts and calculations

6. Revise and evaluate yourself at every step

For further information you can go through with given below link.

GATE Preparation