@Mudit 

If you look below your router, what is the country code that is in parenthesis?

@Tony 

@Mudit 

Thank you for the picture.

A couple of things I would recommend:

1. Make sure you extracted the .zip file and were uploading the .bin file to the router.

2. Reach out to your local support team. The reason being there are two different versions of the firmware for the C20. So if you were using or trying the EU version there is still the US version, and we do have US products in your region. However, your local TP-Link support team would know if that would be an alternative solution or a bad one.