Sir My cet applications and challenge is missing what I do please answer me. ?

Hi there,
Hope you are doing well. Sorry to say but it is too late to search for any methods. You should take utmost care while handling such important documents. Just search it in your house and wherever necessary, and if you still don't find it, just contact the KEA support through email mentioning your problem that you have lost the application and challan and also mention your hall ticket number and ask them for help. The email can be found in their official website. I hope you got the point after reading this answer.
All the best.