The alignement on your character sheet is calculated from your classes and from the alignment that you would prefer to be.
For example, paladin is considered as good, blackguard as evil and sorcerer as what you want.
So if you are 10 Paladin, 10 Blackguard your alignment on your character sheet will be neutral.
If you are 10 Paladin, 10 Blackguard, 20 sorcerer, your alignment will be up to you.

Talk to Vichan in the OOC Lounge to set your preferred alignement.

You can find the preferred alignement of all classes and calculate what your character alignement can be with here:
http://nwn.sinfar.net/p_classesalign.php

Alignment restrictions have been removed from all classes

No one can force you to roleplay the alignment that is on your character sheet, it is even kept private.