You should join coaching institutions and start with fundamental.

From third yesr you should be clear with all basics and fundamental and move into advanced level probkems.
Make sure you have enough practical mock exams appeared to know your weak areas.

Focus on them and spend more time ro resolve and ckear doubts.

Make handy revision notes for revision and saving your time.

All tips compiled below.
https://engineering.careers360.com/articles/how-prepare-for-gate-without-coaching

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