Hello Akshaya,

If you're in Clause C in KCET - as you have undergone the document verification, you will probably first receive a verification slip without the secret key code. The secret key (also referred to as secret code) is generally sent to you via SMS/email later by KEA shortly after verification but before option entry begins.

You do not have to upload any separate document specifically for the secret code. Just keep your mobile number + Email ID active from your KCET application. You could also check the official site regularly if they provide any updates on further information on the secret codes in your messages.