Compiling with OpenSSL 1.0.2j I get:

>>
% package require tls
couldn't load file "/usr/opt/tcl86/lib/tcltls1.7.12/tcltls.so":
/usr/opt/tcl86/lib/tcltls1.7.12/tcltls.so: Undefined symbol "get_dhParams"
<<

Compiling with nss-3.30 I get:

>>
% package require tls
couldn't load file "/usr/opt/tcl86/lib/tcltls1.7.12/tcltls.so": /usr/opt/tcl86/lib/tcltls1.7.12/tcltls.so: Undefined symbol "SSL_CTX_set_client_CA_list"
<<

When compiling the following warnings:

>>
./tls.c: In function 'CTX_Init':
./tls.c:1182:11: warning: implicit declaration of function 'get_dhParams' [-Wimplicit-function-declaration]
      dh = get_dhParams();
           ^
./tls.c:1182:9: warning: assignment makes pointer from integer without a cast [-Wint-conversion]
      dh = get_dhParams();
         ^
./tls.c: At top level:
cc1: warning: unrecognized command line option '-Wno-self-assign'
<<

get_dhParams is defined in dh_params.h, which is included in tls.c if OPENSSL_NO_DH is undefined. Does your OpenSSL installation define this macro ?

This issue is apparently the same as [12bf5e37e0797c824c22ca2c2c0636f31cd4aa22] and it is fixed in TclTLS 1.7.14 and newer.