openssl s_client -connect google.com:443 -tls1_2
If you get the certificate chain and the handshake ok. It supports TLS 1.2. If you don’t see the certificate chain, and something similar to “handshake error” you know it does not support TLS 1.2. You can also test for TLS 1 or TLS 1.1 with -tls1 or tls1_1 respectively.
