How does the trade in work in India - how much time will I have to return my existing phone, or will it happen during delivery of the new phone itself?

Hi,

I currently use an iPhone 11, and and considering ordering the 15 and trading in my 11. When I go through with it, will my existing phone be picked up at the time of delivery (as I have experienced for example with Amazon) or will I have some time to transfer and setup from my existing phone, and the pickup will be on a separate date (as I have experience for example with Flipkart).

Also will the existing phone be picked up, or I will get a kit in which I have to keep and send/courier the phone? Asking since it 's my first time doing a trade in via the apple India website. I have ordered in the past, but never had to trade in.