Not as much as you would think. NWN resembles older bioware games like baldur's gate and icewind dale more than it does KOTOR.
The similarities are that you have multiple dialogue and action choices in NWN like you do in KOTOR. In fact, I think you have more such options in NWN than in KOTOR. But the story is worse on NWN, and since it's older, its gameplay is less refined than in KOTOR. I enjoyed KOTOR combat much more than I did NWN combat.
I did enjoy NWN personally, but some thought it was something of a letdown, more a showcase of the aurora toolset (at least I think that's what it's called) than a great game.