Hi Isha with only 15 days left you shoild definitely focus on solving previous year questions.

While solving the questions if you feel like that you have forgotten some of the formula our concepts you shoukd revise that.The more you practice the best marks you will score .Don't try to read that formula which you have not used before .It would be a waste of time and you won't credit from it.

Hope you get good marks in GATE.

ALL THE BEST!