Linked Server Setup Error - SSL Provider: The client and server cannot communicate, because
Ensure both servers have support for TLS 1.2.

The following table, taken from the Microsoft Support site, shows when TLS 1.2 support was added to each particular SQL Server version:

╔═════════════════════════════════════════╦══════════════════════════════════════════╗
║           SQL Server release            ║    First build that supports TLS 1.2     ║
╠═════════════════════════════════════════╬══════════════════════════════════════════╣
║ SQL Server 2014 SP1                     ║ 12.0.4439.1                              ║
║ SQL Server 2014 SP1 GDR                 ║ 12.0.4219.0                              ║
║ SQL Server 2014 RTM                     ║ 12.0.2564.0                              ║
║ SQL Server 2014 RTM GDR                 ║ 12.0.2271.0                              ║
║ SQL Server 2012 SP3 GDR                 ║ 11.0.6216.27                             ║
║ SQL Server 2012 SP3                     ║ 11.0.6518.0                              ║
║ SQL Server 2012 SP2 GDR                 ║ 11.0.5352.0                              ║
║ SQL Server 2012 SP2                     ║ 11.0.5644.2                              ║
║ SQL Server 2008 R2 SP3                  ║ 10.50.6542.0                             ║
║ SQL Server 2008 R2 SP2 GDR (IA-64 only) ║ 10.50.4047.0                             ║
║ SQL Server 2008 R2 SP2 (IA-64 only)     ║ 10.50.4344.0                             ║
║ SQL Server 2008 SP4                     ║ 10.0.6547.0                              ║
║ SQL Server 2008 SP3 GDR (IA-64 only)    ║ 10.0.5545.0                              ║
║ SQL Server 2008 SP3 (IA-64 only)        ║ 10.0.5896.0                              ║
╚═════════════════════════════════════════╩══════════════════════════════════════════╝


If you have a version of SQL Server prior to those listed in the above, you should apply the latest service pack and cumulative update to enable TLS 1.2 support.

https://sqlserverbuilds.blogspot.com and https://sqlserverupdates.com/ contain excellent resources detailing where to get the latest updates for SQL Server.