What is cuet pg?
Is it just the studying you struggle with, or learning in general? What level are you at?
Ultimately, the people who best put the time in. You can often achieve a pass with limited time, but to do better than the best, you need to do the work.
Look at the syllabus and what you need to know, what you already know, what your weak spots are. There will probably be areas you need to know I more depth than others, so they might be areas to focus on, but you should have at least a general understanding of everything that will be covered by minimum requirements.
Make notes and prompt cards and test yourself. If you don't do well on the self-test, do more learning until you can. I find writing helps me absorb it more than typing, so go analogue.
But if you want to do really well, you need to do the work. Even really talented sportspeople or musicians have to keep practising to reach the top and stay there.