By default, Xcode inserts a company name something similar to the following in all new source files (.m .h etc):
//
//  ViewController.h
//  MyApp
//
//  Created by _username on 08-05-13.
//  Copyright (c) 2013 MyCompanyName. All rights reserved.
//

If you want to fill the Author and Organization name automatically  for the _username and MyCompanyName. Follow the simple steps given below.

Option 1: (Xcode 4.x)

Open up the address book (Address Book is by default the first app in your Applications folder.) and create a contact with the name and company information you want to fill with for each file when it is created.

Contact Creation
Now select the Card  menu item and  choose Make This My Card.

Make My ContactNow  try creating a file/project through xcode, all the files created should have headers filled with the information from the contact you have created.

(or)
Open up the address book and go to your user account, and edit your name (the large, bold line at the top).
If you don’t know which contact is your user account: Open up System Preferences. Go to Users & Groups (in the System row); your user account should already be selected. Click on the “Open…” button for the Address Book Card.
Note: Changing your name in the Address Book won’t change any already-created files; it will only affect new files that you create.

Option 2:

Changing this reference is as simple as entering the following from within a terminal window, replacing “YourNameHere” with the text you prefer. Also, make sure this is all entered on one line in the terminal.defaults write com.apple.Xcode PBXCustomTemplateMacroDefinitions ‘{ORGANIZATIONNAME=”YourNameHere”;}’
OR
you could even go to ~/Library/Preferences and double-click com.apple.Xcode.plist and use the handy-dandy plist editor to set this and a whole bunch of other interesting defaults not covered by the Xcode or IB preference panels.
OR
in the navigation pane (far left side), select the project (top item).
Expand the Utilities pane (at window top-right, far right button in the 3-button “View” group).
In the “Project Document” section is the “Organization” text field (File Inspection view, second section from top).