With the exception of the 4D Web Area, TLS Support within 4D is dependant upon the version of OpenSSL used within 4D; the openSSL version used by 4D can be found via the following tech tip: How to Find the Version of OpenSSL used in 4D

This table may also help identify which version of TLS are currently supported within 4D:

4D version	openSSL version	TLS version supported
13.0 - 13.5	1.0.0.4 (d)	TLS v1.0
13.6	1.0.1.12 (i)	TLS v1.2
14.0 - 14.3	1.0.0.4 (d)	TLS v1.0
14.4+	1.0.1.12 (i)	TLS v1.2
15.0+	1.0.1.12 (i)	TLS v1.2

Correction - November 4th, 2015:
OpenSSL 1.0.1 supports TLS 1.2 in addition to TLS 1.1