As per Diagnosing TLS, SSL, and HTTPS article for JDK 8 default TLS protocol is TLS1.2 so you don't have to do anything.
If your JDK is using different default protocol you can override it by adding the next line to user.properties file:
https.default.protocol=TLSv1.2
JMeter restart will be required to pick the property up.
More information:
However your problem: Connection timed out: connect doesn't have anything in common with HTTPS version, it indicates that JMeter failed to establish the connection with the server within the default timeout time frame, you need to look into the connectivity issues, for example it might be the case you need to configure the proxy