Hope you are doing well.
1. Can I make payment through PayPal or WireTransfer is must ?
>>>See, you have to pay with bank wire transfer/TT because you are ordering stock.We use Paypal only for sample product payment.
2. After payment, should we apply for UPC code? Can you please explain this process in detail?
>>>You can apply anytime for UPC codes.For UPC codes you need to create a ticket here than we provide you 10 free UPC codes.
See, it depends on you-you can start sidewise but it suggests first sell on Amazon than once sales come than start on Flipkart.
If you further have any query you can rise here.