Congratulations on your outstanding achievement of scoring 99.5 percent in Class 12th with full marks in Physics, Chemistry, and Mathematics. This is an exceptional academic performance, and it places you among the top-performing students in the country. BITS Pilani does offer direct admission to students who are toppers of their respective Class 12 boards. If you are officially declared as the topper of your board (for example, CBSE, ISC, or the Andhra Pradesh state board), you may be eligible for direct admission to the BITS campus of your choice, without appearing for the BITSAT exam. This direct admission is offered to board exam toppers as a special privilege, and it allows them to choose the program they wish to pursue. However, scoring 99.5% alone does not guarantee direct admission unless you are confirmed as the overall board topper. If you are indeed the topper, you should visit the official BITS admission website and apply through the dedicated board topper admission process. You will need to submit proof of your board rank and relevant academic documents as part of the application. If you are not the board topper, then you will need to appear for BITSAT, but your strong academic background should give you a good foundation for success in the entrance exam.

Best of Luck.