Hello student its good that you're thinking and worried about how many times you should study and revise things. But according to my experience scoring 95 percent in class 12 is not a very tough. What exactly you have to do is focus on things that teachers taught you in class mostly students didn't score well just because they didn't pay focus in class and later face problems.

Before starting any chapter/topic  just do a 5-10 min overview about that chapter that'll help you in better understanding.

Once you're done with the whole syllabus then don't revise it fully second time just mark the questions which you felt tough during solving it and only solve them during revision.

2-3 time revision is enough for class 12 to score more than 95%.

Feel free to comment if you have any doubt
Good luck

Hello Abhishek,
It is not fixed actually, it depends on the mind of the Student that how is getting the things which are important for him.There is no fixed criteria of revision  to get the 95 percentage in 12th whether you are from any board. If you getting the things correctly and not forget those thing which are important. Then there is no need of revision. But if you are getting things forgetable, then yes you have to revise them again and again until to get remember them.