I have apps like A Better Finder Rename on my Mac for batch renaming files. It is very sophisticated, very powerful. But, if you do not wish to buy a standalone app for this purpose (they can be a little expensive) you can still do it using the macOS Finder.
Finder Batch Rename
To demonstrate this Finder functionality I have created three files in a folder. I am using macOS El Capitan. Here are the files selected in “Icon View”:
Once you select the files then go to the “Rename” command in the “File” menu. Once you choose the “Rename” command the Finder presents this window with a dropdown menu:
You have three choices which are fairly versatile, Replace Text, Add Text, Format. You can rename the files, add stuff to the end of the files or the beginning. You can rename them sequentially. You can do some formatting as well:
As you can see the batch renaming feature of the macOS is fairly complex. It would certainly be enough for many people that do not need the horse power of an app like A Better Finder Rename.
If you find yourself needing to do some batch renaming of files on your Mac look no further than your Finder! It may have just enough power to do the job.