If SMS messages show a status of "Delivered" but aren't appearing on the recipient's mobile phone in India, several factors could be contributing to this issue. Here are some possible explanations and troubleshooting steps:

1. **Network Issues**: The recipient's mobile network may be experiencing temporary outages or service disruptions. This could affect the delivery of SMS messages.

2. **Phone Settings**:

   - **Blocked Numbers**: The recipient might have accidentally blocked your number, preventing messages from appearing.

   - **Do Not Disturb (DND)**: If the recipient has enabled DND services, they may not receive promotional or certain types of messages.

3. **Message App Issues**: The recipient's messaging app might be malfunctioning or require an update. Encourage them to:

   - Restart the app.

   - Clear the app's cache or data (if using Android).

   - Update the app or switch to a different messaging app temporarily.

4. **SIM Card Issues**: If the recipient's SIM card is damaged or improperly inserted, it could affect message reception. Suggest that they try:

   - Removing and reinserting the SIM card.

   - Testing the SIM in another phone to determine if the issue is with the SIM or the device.

5. **Storage Issues**: If the recipient's device is low on storage, it may not be able to receive new messages. The recipient should check their available storage space and delete unnecessary files or apps.

6. **Sender's Network**: Sometimes, issues may arise from the sender's network or SMS gateway. If possible, try sending an SMS through a different service or network.

7. **Carrier Restrictions**: Some carriers may have restrictions on certain types of messages or numbers. The recipient should check with their service provider to ensure there are no issues on their end.

8. **Try Alternate Communication**: If the SMS communication continues to be problematic, consider reaching out through other methods (e.g., WhatsApp, email, or a phone call) to confirm that the recipient is aware of the messages you are trying to send.

If the issue persists after checking these factors, both the sender and recipient may want to reach out to their respective mobile service providers for further assistance.