is any need to join for any coaching class to get good marks in gate exam?

No, it is not necessary to join any coaching institute to crack GATE exam.

You can follow below strategy to crack this exam

-Since there are many subjects included in the syllabus, it is important that you should observe complete syllabus.

-Know Weightage for each subject based on previous year papers  and target your preparation to carry more marks in GATE exam.

-Try to understand the concepts, practice tests and revise regularly

-Most of the questions in GATE are conceptual & numerical, so you must try to improve your solving ability & time management to score a good rank.

-Make a revision notes for each topic that should cover all important definition, formulas, differences, etc.

-Practice topic wise previous GATE questions after understanding the each topic.
You can practice the mock tests in two ways. One is self practice on daily basis, and other is attempting online mock tests.

Good Luck!!

It depends on you only as if your all basics are clear and you just need to revise the syllabus then you can go for self study only but if you need a mentor or someone who can make all your basics clear then you can join coaching. Basically, it depends on your need and requirement so please tell which year you are preparing for and what is your preparation status?