[Kostas']

First of all you have the same NPC 2 times

pawn Код:

public OnGameModeInit()
{
  ConnectNPC("MyFirstNPC","area51tank1");
  ConnectNPC("MySecondNPC","area51tank2"); //If you want 2nd npc
  return 1;
}

Then if the npc are on vehicl you should kreate one for them

pawn Код:

new MyFirstNPCVehicle; //MyFirstNPC replace the NPC's name if you want to change it

If the NPC is on foot skip this

pawn Код:

public OnPlayerSpawn(playerid)
{
  if(IsPlayerNPC(playerid)) //Checks if the player that just spawned is an NPC.
  {
    new npcname[MAX_PLAYER_NAME];
    GetPlayerName(playerid, npcname, sizeof(npcname)); //Getting the NPC's name.
    if(!strcmp(npcname, "MyFirstNPC", true)) //Checking if the NPC's name is MyFirstNPC
    {
      PutPlayerInVehicle(playerid, MyFirstNPCVehicle, 0); //Putting the NPC into the vehicle we created for it.
    }
    return 1;
  }
  //Other stuff for normal players goes here!
  return 1;
}