First send them email, requesting for network conversion. If they deny, then tell them about the rbi mandate. I have attached the doc, so you can read. Attach this in the email.
You can after you get the card. At first, I called the customer care and they said it's not possible. Then, I emailed them with mentioning about the RBI guideline with attaching the doc for it. Within few days, I got the call that they are processing the network conversion request for the card.
Sometimes i feel like this happens because of the area being unservicable.
Edit - I tried to apply for the card now and got it instantly 😂. I got "no offers" too last 2 times. I got signet visa with 1.9 lac limit.