see tcl version code example
Example 1: see tcl version
bash-3.2$ tclsh
% puts $tcl_version
8.6
% info patchlevel
8.6.0
Example 2: see tcl version
puts $tcl_version
bash-3.2$ tclsh
% puts $tcl_version
8.6
% info patchlevel
8.6.0
puts $tcl_version