Hi There,
This is a very important question which every aspirant should know an answer to, if he is not sure of getting a seat in IIT.
Unlike top rankers, most of the aspirants are in the dilemna whether they will get a seat or not. How much paper they should attempt? How to judge whether the paper is tough or not and so many other similar questions.
What I have been telling all my students is a simple mantra.
Think as if you have to attempt any one of the two consecutive questions. That means you need to attempt around 50% of the paper.
Even if you can get around 40 % overall marks you should be able to score around 2500 rank which is a very decent rank for someone who is not sure whether he will get a seat or not.
Therefore, just try to attempt 50% , stay calm, give your best and you will surely get a decent rank in JEE Advanced.