Hey, congratulations on such an amazing rank.

For undergraduate level, indian institutes of technology do not offer petroleum engineering as a course. You will have to take up chemical engineering and then pursue petroleum engineering in your post graduate. iitm and iitb definately offer them in PG. All the best

Hey there

First of all congratulations for your rank as you are in the toppers of JEE advanced this year. You have decent chances of getting CSE in top iits like IIT Bombay, Delhi etc.

Check JEE advanced cutoff

https://www.google.com/url?sa=t&source=web&rct=j&url=https://engineering.careers360.com/articles/jee-advanced-cutoff/amp&ved=2ahUKEwjuvePfyOriAhUX3Y8KHe_4C4UQFjAHegQIAhAB&usg=AOvVaw2VOKI-nLKDIek2nav5VUOi&ampcf=1

Good luck