Honestly, CIBIL score is only one piece of the puzzle. Banks have their own internal scoring systems on top of CIBIL — HDFC especially is known for being strict this way. A 780 gets you in the door, but it doesn't guarantee approval. Let me tell you what's likely going wrong here.
First — salary. ₹52k in hand for HDFC Regalia is borderline. Regalia typically wants ₹1 lakh+ in hand or an existing HDFC relationship. That card is genuinely a premium product and they're picky about it. This is probably your main issue.
Second — your credit profile is thin. One card with ₹40k limit, no loans, 3 years of history. Banks call this a 'thin file.' Your score is good but there's not much data for them to feel confident about giving you a high-limit premium card.
Third — the thing most people get wrong — they don't check if they had too many hard inquiries recently. Every time you apply for credit, it shows on your CIBIL report. Even one or two extra applications in 6 months can trigger rejection at conservative banks like HDFC.
What you should actually do:
Don't apply to multiple cards right now. Every rejection adds a hard inquiry and makes things worse. Wait at least 3-4 months.
Open a savings account with HDFC if you don't have one. Salary account especially. HDFC gives preferential treatment to their own account holders. Even a 6-month old HDFC relationship changes how they look at your application.
Apply for a more appropriate card first — try SBI SimplyCLICK or Amazon Pay ICICI. These are easier to get at your income level and will thicken your credit profile over the next 12 months.
After that, reapply for Regalia or try HDFC Millennia which has lower income requirements.
Also raise a limit increase request on your Axis card. A higher limit with low utilization actually improves your score over time.
My recommendation — go get the Amazon Pay ICICI card right now (no joining fee, good cashback, ICICI is relatively easy to approve). Use it for 12 months alongside your Axis card, keep utilization under 30%, then go back to HDFC. You'll get approved easily at that point.