See it may create problem during the document verification. Now if you have provided the wrong number, then thinking of it now is immaterial. So while you will be visiting for physical Document verification then keep both the certificates with you i.e., both the old and the new one. If the officials ask then show them both. There are no major possibilities of cancellation or any big trouble but you may have to give necessary justification for your mistake and show them the proofs.

To know more about KCET visit the link below:

https://www.careers360.com/exams/kcet

I hope this answer helps. All the very best for your future endeavors!