Why the mobile phones indicates "Emergency call" through adiquate network is available?

When a mobile phone indicates "Emergency call only" or "Emergency calls only" even though there is adequate network coverage available, it typically means that the phone is not registered on the network or is not authorized to make regular calls. This could be due to a number of reasons, such as:

1. The SIM card is not inserted properly or is damaged.
2. The phone is not compatible with the network frequency bands.
3. The phone has been blacklisted by the network provider.
4. The phone is locked to a specific network and needs to be unlocked.
5. There may be a temporary issue with the network provider's system.

In these cases, the phone is still able to make emergency calls because it is required by law for all mobile phones to be able to connect to emergency services even without a SIM card or network registration. This ensures that individuals can still call for help in emergency situations, even if they do not have a valid network connection.