how to get 60 plus in ca final audit and law??

I can say about Law only.
The main issue students face is NOT learning of the legal provisions, BUT understandig the question and application of the provision.
I would suggest alongside studying from your reference book, after each topic, pick up the PM/RTP/MTP, find the questions of that topic and write them in your own words.
Then check your answer via a vis the ICAI solution and highlight the gaps.