These tools are additional to the standard AIX tools of the same name, so your script will have to change the PATH variable or use a full path name to the GNU tools to utilize them.
... and as always that should be done, and you should stage this on a development platform and confirm how to do the install, document the install details, and test results, and have it reviewed before you move this to a production environment.
Confirming (testing) how it works on AIX6.1 is your responsibility in your own development and test environment, not ours, obviously.