Hello Aspirant,

You need to do it online .

After the allotment of seats in your login portal there will be option to cancel the seat .

There are terms and conditions  in cancellation of seats in KEA .

The candidates have to cancel the seat through online and through a single-window system by using the log-in portal only.

The candidates have to cancel the seat through online and through a single-window system by using the log-in portal only.

Candidates have to select the appropriate link for the cancellation of a seat and complete the procedure for cancellation of a seat.

After cancelling through online candidates have to download cancellation order compulsorily.

For more information check this link:

https://engineering.careers360.com/articles/kcet-seat-allotment