I am using Altium Designer 16.1 for a project which has about 6 thousands of components, so I have many Net Lables(at first I designed a small circuit in a schematic page then by copy and paste I create the whole project). I used Annotate Schematics option in the "Tools" menu to rename the components, Is there any option to rename the Net Lables automatically like annotate option?
EEK.. unless you can edit that in a text file or something you may be out of luck..
For future reference, the better method for something like this is to make your design hierarchical.
Create a single page with the common circuit with an associated symbol, then instantiate N of those symbols on an interconnecting schematic page.
The software should handle the rest.