I would like to congratulate you on your great performance. You did a good job !! You are among the Top 10000 among 10 lakhs students (approx). I believe this is a result of your hardwork and good preparation. But this is not the time for relaxation or complacent.
You still have JEE Advanced left which matters the most. Keep up your hardwork and preparations. Revise the concepts you feel you aren’t confident about. And yes, don’t forget to PRACTISE. Solve Previous Year’s papers as much as possible.
Don’t get distracted or nervous or over-confident.Stop being afraid of what could go wrong and start being positive about what could go right.Keep calm and do your best. If you are having feelings that your Mains rank might not be good enough or likewise, then squash them now. Dont worry about what branch or colleges you might get and stuff. There is good chance you will do better in Advanced. Trust me what matters is your end result. Do keep in mind the differences between Mains and Advanced and continue your preparations.
So for now your best option would be to stay calm,confident and focussed. Keep up with your preparation and practise. Don’t worry about your rank now,time will come when you will have to.