By default, Mac OS X Sierra sets all downloaded files to "quarantine". This prevents you running the Studio.
To launch Talend Studio on Mac OS X Sierra, do the following:
Unzip the Studio as usual.
Open a Terminal window on the folder where you unzipped your Studio.
Execute either of the following commands.
xattr -d com.apple.quarantine *
xattr -c *
You can now launch the Studio as usual.