• Hardwork and strong determination leads you to excel to come under that zone.
• Making the proper notes and practice enough numericals for each and every topics from every domain.
• Practice enough number of numericals and sample papers of previous years IIT-JEE paper such that you will come to know about the scenario of JEE Mains and Advance.
• And lastly don't divert your mind and believe on yourself's preparation.

For getting top 100 ranks you must first clear Jee Main within 2.31 lakh candidates and appear for Jee Advanced and get scores above 320 for top100rnaks. 

Excellent preparation from NCERt books as well as advanced books and clear fundamental is key. Solving more than 30 mock exams and rectify all mistakes and doubys is critical to score well. 

Daiky revision also shall work wonders. 

Jee advanced tips by toppers below. 

https://engineering.careers360.com/articles/jee-advanced-preparation-tips-physics-chemistry-and-mathematics