Believe me, it isn’t a silly question. After the amount of hard-work people put in for getting even a rank in JEE Advance it’s no short of an achievement to celebrate it. But at the end it’s only a qualifying exam. Just as your 10th Class Board Examination results don’t matter after you’ve taken admission in a Junior College (exception: IIM interview), your JEE Advance rank is useless.
Coming to the topic of placements, your CGPA in BITS Pilani will matter a bit during placements as will your experience in internships as also the skills you’ve developed in college after getting in BITS Pilani. Make sure you work on these after you get into college.
Best of luck for your future and hope this answer helps you in clearing your confusion. 🙂