It was on COD.
But it is the habit of Flipkart that it intentionally rejects or cancelled orders as with my previous ones. So it's a kind of customer irrelevant service.
I have ordered a small tricycle for my Sister's daughter on 6th of Nov, 2024 and it was shown to be delivered on 15th of Nov, but it was cancelled by Flipkart as the price was low earlier and rised immediately after I ordered.