Copy the .nk2 file in following folder:
Make sure .nk2 file’s name is same as your current outlook 2013 profile. By default, the profile name is ‘Outlook’. You can check profile name by following these steps
Go to control Panel, Double Click Mail
In Mail setup dialog box, click Show Profiles
After making sure the .nk2 file’s name is same as your outlook profile, do following steps
Click Start, and then click Run.
In the Open box, type outlook.exe /importnk2 . This should import the .nk2 file into the Outlook 2013 profile.
If it doesn’t import .nk2 file try following
Click Start, and then click Run
type: C:\Program Files\Microsoft Office 15\root\office15\outlook.exe /importnk2