Root your I8200N Last z3x tool click info and Click unlock I8200N unlock done.

How to for I8200N unlock

download vroot Get vroot_English version_Oneclick root tool.

Root your I8200N

Last z3x tool

click info

and

Click unlock

I8200N unlock done.

Code:

Selected model: I8200N
Selected port: 
Selected port speed: 115200
Searching ADB device...
Please, allow USB debugging on phone... OK
Reading phone info...
Model: GT-I8200N
Android version: 4.2.2
Product code: GT-I8200RWNVIT
Phone version: I8200NXXUANG1
PDA version: I8200NXXUANG1
CSC version: I8200NVITANG1
IMEI: 359xxxxxxxxxxxx
Phone S/N: R21Fxxxxxxxx
Checking Super user right... true
Bypass MSL... OK
Unlocking... OK
Rebooting phone... OK
Unlock done
Done with Samsung Tool v.18.1