"RuleSets": [{
  "name": "default",
  "enabled": true,
  "defaultAllowDamage": false,
  "flags": "HumanNPCDamage, LockedBoxesImmortal, LockedDoorsImmortal",
  "rules": ["anything can hurt dispensers", "anything can hurt players", "players cannot hurt players", "anything can hurt traps", "traps cannot hurt players", "players can hurt barricades", "barricades cannot hurt players", "highwalls cannot hurt players", "anything can hurt heli", "anything can hurt npcs", "fire cannot hurt players", "anything can hurt resources", "samstatic can hurt airtransports", "murderers cannot hurt scientists", "scientists cannot hurt murderers", "murderers cannot hurt animals", "scientists cannot hurt npcs"]
}], "Allow Killing Sleepers": false, "Entity Groups": [{
  "name": "dispensers",
  "members": "BaseCorpse, HelicopterDebris",
  "exclusions": ""
}, {
  "name": "players",
  "members": "BasePlayer",
  "exclusions": ""
}, {
  "name": "traps",
  "members": "AutoTurret, BearTrap, FlameTurret, Landmine, GunTrap, ReactiveTarget, spikes.floor",
  "exclusions": ""
}, {
  "name": "barricades",
  "members": "Barricade",
  "exclusions": ""
}, {
  "name": "highwalls",
  "members": "wall.external.high.stone, wall.external.high.wood, gates.external.high.wood, gates.external.high.wood",
  "exclusions": ""
}, {
  "name": "heli",
  "members": "BaseHelicopter",
  "exclusions": ""
}, {
  "name": "npcs",
  "members": "NPCPlayerApex, BradleyAPC",
  "exclusions": ""
}, {
  "name": "fire",
  "members": "FireBall",
  "exclusions": ""
}, {
  "name": "resources",
  "members": "ResourceEntity, TreeEntity, OreResourceEntity",
  "exclusions": ""
}, {
  "name": "airtransports",
  "members": "minicopter, minicopter.entity, scraptransporthelicopter, hotairbaloon",
  "exclusions": ""
}, {
  "name": "samstatic",
  "members": "sam_static",
  "exclusions": ""
}, {
  "name": "animals",
  "members": "bear, boar, chicken, horse, stag, wolf",
  "exclusions": ""
}, {
  "name": "scientists",
  "members": "NPCScientist, Scientist, scientist_junkpile, scientist_gunner, scientistpeacekeeper, NPCscientist_junkpile, NPCscientist_gunner, NPCscientistpeacekeeper",
  "exclusions": ""
}, {
  "name": "murderers",
  "members": "murderer, NPCMurderer",
  "exclusions": ""
}]
}​

Hello and Thanks for reply,

I tried, so became:
{
"name": "scientists",
"members": "NPCScientist, Scientist, scientist_junkpile, scientist_gunner, scientistpeacekeeper, NPCscientist_junkpile, NPCscientist_gunner, NPCscientistpeacekeeper, NPCPlayer",
"exclusions": ""
},
{
"name": "murderers",
"members": "murderer, NPCMurderer, NPCPlayer",
"exclusions": ""
}
and nothing... still issue

put this in a file and save it as NoApexTargetting.cs

this will not work for magenta npcs in AdminRadar as those are HTNPlayer

namespace Oxide.Plugins
{
    [Info("No Npc Targetting", "nivex", "0.1.0")]
    [Description("Prevent npcs from targeting other npcs.")]
    public class NoNpcTargetting : RustPlugin
    {
        private object OnNpcTarget(BaseEntity e1, BaseEntity e2)
        {
            return e1.IsNpc && e2.IsNpc ? true : (object)null;
        }
    }
}

save as NoNpcTargetting.cs. prevents all npcs from targeting any npcs :p