Hi @Prajkta Patil,
Thank you for your replay.
When SharePoint Server fails to connect to SQL Server, the question "This operation can only be performed on computers that have joined the server farm" usually appears.
Please refer to this article to troubleshoot the problems one by one: Operation can be performed on computer that is joined to server farm.
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According to the official configuration documentation, you do need to make all the settings to enable TLS1.2 in SharePoint.
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