Unable to access 5g

What? Which Metro city are you from?

https://www.airtel.in/5g-network/

Please read this section in the FAQ.

When will I start experiencing Airtel 5G? 

"We’re ready to launch Airtel 5G services from Oct’22. By December, we will have coverage in all key metros. By end of Dec 2023, we will have 5G coverage across all major cities of India."

Apple will push a OTA update which will enable 5G services on iPhones, so at this point, we just have to keep waiting. Hope this helps!