Sit the paper at the same time of day as the actual JEE Main shift if you can. Same desk, same rough environment, no phone in the room.
Mocks only work if the timing and the marking are real
A mock test is a measurement instrument, not a practice worksheet. If the timer pauses when you lose focus, if there is no negative marking, or if you can check an answer mid-paper, you are measuring nothing. The mock tests here run at the real 180 minutes, apply the real marking scheme including negative marking for wrong answers, and hide solutions until submission. After you submit, you get a score breakdown by subject and chapter, a list of the questions you got wrong, and an estimated All India Rank band so the number means something outside your own notebook. The uncomfortable part is the point: a mock that never hurts is a mock that never teaches.