Dear Pooja,  now during the correction window, you can change your Exam papers that you want to appear for. So when the correction window opens, you can only select as you want to appear for B.Tech instead of B.Planning. The balance amount will not be refunded though but it gives you less to worry about. Now lets say when the correction window opened on October 14th and you were not able to change the exam paper, it will not have any bearing on your JEE Main rank. Not attempting a paper will not be counted as an attempt that can affect your ranking. So please wait for the correction window to open so that you can make the necessary changes.