On my galaxy watch 4 LTE version I cannot send or receive sms with out connecting to my samsung phone.but I can call through watch with out connecting to my phone..Iam using jio sim.
As per your concern kindly perform the following steps to resolve your issue:
The following features can be used for sending messages on Galaxy Watch:
If you want to take a break from your jog and send a Quick message to a friend, you can do that easily on your watch using the Messages app. Make sure your watch is connected to your phone or to a mobile network. Note: This function is only available when connected to a Galaxy phone. It is not available on non-Samsung phones or iOS devices.
Step 1: Navigate to and tap Messages. To compose a new message, select either the message icon or the contact icon. Note: The message icon may not appear if you've never sent a message on the watch before.
Step 2: Enter or choose your recipient. If you want to send a reply to an existing conversation, select the message from the log instead. Step 3: There are many methods to choose from when it comes to creating or replying to a text.
When replying to a group message, replies will be sent back to the entire group. To reply to an individual recipient, tap More options (the three vertical dots) located to the right of the screen, and then tap Recipients. Select the desired recipient, and then tap the Messages icon.
In case the issue still occurs, please visit the service center for a physical inspection of your device. You can locate your nearest service center with this given link: https://www.samsung.com/in/support/service-center/
