If you download the Intel version (I have downloaded v7.0, you can download 6.1.4) in the Downloads directory, then
1. ls testdisk-7.0-WIP.mac_intel.tar.bz2
testdisk-7.0-WIP.mac_intel.tar.bz2
2. bunzip2 testdisk-7.0-WIP.mac_intel.tar.bz2
3. ls testdisk-7.0-WIP.mac_intel.tar
testdisk-7.0-WIP.mac_intel.tar
4. tar tvf testdisk-7.0-WIP.mac_intel.tar
drwxr-xr-x 0 kmaster kmaster 0 Sep 13 04:02 testdisk-7.0-WIP/
-rwxr-xr-x 0 kmaster kmaster 1924576 Sep 13 04:02 testdisk-7.0-WIP/testdisk
-rw-r--r-- 0 kmaster kmaster 216 Nov 11 2007 testdisk-7.0-WIP/AUTHORS
-rw-r--r-- 0 kmaster kmaster 17987 Jun 15 2006 testdisk-7.0-WIP/COPYING
drwxr-xr-x 0 kmaster kmaster 0 Sep 13 04:02 testdisk-7.0-WIP/ico/
-rw-r--r-- 0 kmaster kmaster 2238 Sep 28 2006 testdisk-7.0-WIP/ico/photorec.ico
-rw-r--r-- 0 kmaster kmaster 7406 Mar 5 2009 testdisk-7.0-WIP/ico/testdisk.ico
-rw-r--r-- 0 kmaster kmaster 129560 Mar 5 2009 testdisk-7.0-WIP/ico/testdisk.icns
-rw-r--r-- 0 kmaster kmaster 16685 Aug 5 2013 testdisk-7.0-WIP/NEWS
-rw-r--r-- 0 kmaster kmaster 1667 Aug 9 03:55 testdisk-7.0-WIP/testdisk.8
-rw-r--r-- 0 kmaster kmaster 117 Jan 8 2014 testdisk-7.0-WIP/INFO
-rwxr-xr-x 0 kmaster kmaster 505624 Sep 13 04:02 testdisk-7.0-WIP/fidentify
-rw-r--r-- 0 kmaster kmaster 344 Apr 21 2008 testdisk-7.0-WIP/THANKS
-rw-r--r-- 0 kmaster kmaster 239 Mar 10 2012 testdisk-7.0-WIP/readme.txt
-rw-r--r-- 0 kmaster kmaster 1082 Aug 9 03:55 testdisk-7.0-WIP/photorec.8
drwxr-xr-x 0 kmaster kmaster 0 Sep 13 04:02 testdisk-7.0-WIP/78/
-rw-r--r-- 0 kmaster kmaster 1415 Jun 19 2004 testdisk-7.0-WIP/78/xterm-color
-rw-r--r-- 0 kmaster kmaster 312 Apr 16 2011 testdisk-7.0-WIP/documentation.html
-rw-r--r-- 0 kmaster kmaster 38 Sep 13 04:02 testdisk-7.0-WIP/VERSION
-rw-r--r-- 0 kmaster kmaster 530 Aug 9 03:55 testdisk-7.0-WIP/fidentify.8
-rw-r--r-- 0 kmaster kmaster 2085 Jun 27 2012 testdisk-7.0-WIP/README
-rwxr-xr-x 0 kmaster kmaster 2177480 Sep 13 04:02 testdisk-7.0-WIP/photorec
5. tar xvf testdisk-7.0-WIP.mac_intel.tar
x testdisk-7.0-WIP/
x testdisk-7.0-WIP/testdisk
x testdisk-7.0-WIP/AUTHORS
x testdisk-7.0-WIP/COPYING
x testdisk-7.0-WIP/ico/
x testdisk-7.0-WIP/ico/photorec.ico
x testdisk-7.0-WIP/ico/testdisk.ico
x testdisk-7.0-WIP/ico/testdisk.icns
x testdisk-7.0-WIP/NEWS
x testdisk-7.0-WIP/testdisk.8
x testdisk-7.0-WIP/INFO
x testdisk-7.0-WIP/fidentify
x testdisk-7.0-WIP/THANKS
x testdisk-7.0-WIP/readme.txt
x testdisk-7.0-WIP/photorec.8
x testdisk-7.0-WIP/78/
x testdisk-7.0-WIP/78/xterm-color
x testdisk-7.0-WIP/documentation.html
x testdisk-7.0-WIP/VERSION
x testdisk-7.0-WIP/fidentify.8
x testdisk-7.0-WIP/README
x testdisk-7.0-WIP/photorec
6. You can run it as ./testdisk-7.0-WIP/testdisk
7. There is an example on the Testdisk web site of a step-by-step NTFS recovery that you can follow.