Airtel — Airtel Sim showing not Registered

My Airtel number is +91 [protected]. My sim suddenly stopped showing signal since last week. I always do International Roaming recharge. Even now, I have done Airtel Roaming recharge and it is shown in the mobile app, that it will automatically get activated once the Sim reaches UAE/International area.
I tried rebooting the phone multiple times and even switched the sim to different Phones but still not able to find signal.
Kindly check and advise.