Note : I will be using ZCMD so i hope you have the include and you must define it

#include <zcmd>

new GateOpen;//To check if the gate is opened or not
new Gate;//To save the gate variable. We will use it soon so remember it :D
new stock GateTimer; //This is used so we don't need to make two commands i.e open and close. Timer for closing

Gate = CreateObject(modelid,Float:X,Float:Y,Float:Z,Float:rX,Float:rY,Float:rZ,Float:DrawDistance = 0.0);

/* A example for you :)*/
public OnFilterScriptInit()
{
    gate=CreateObject(987,1496.59997559,-699.75000000,93.80000305,0.00000000,0.00000000,0.00000000); 
        return 1;
}

CMD:(gate, playerid, params[])
{
     if(GateOpen == 0)
     {
          MoveObject(Gate, newx, newy, newz, rate);/*This will move the object to a new coordinate wherever you want*/
          GateOpen = 1;//It means that the gate is opened now
     }
     else
     {
          MoveObject(Gate, originalx, originaly, originalz, rate);// It is the object coordinate which you defined in Gamemodeinit/Or Filterscriptinit.
          GateOpen = 0;//It won't open gate as its already opened.
     }
     }
     else
     {
          SendClientMessage(playerid, color, "You are Far Away.");/*SendClientMessage is use to send a message to the client/user. Playerid=His ID , Color= What color you want the text to be displayed it.*/
     }
  
     return 1;

command(gate, playerid, params[])
{
     if(IsPlayerInRangeOfPoint(playerid, 5.0(range), x, y, z))//The Range you want that player can use the command
     {
          if(Player[playerid][Group] == (Insert Your Gang or Faction Id)) /*Write the id or with whatever you defined them so that only they can open the gate*/
          {
               if(GateOpen == 0)
               {
                    MoveObject(Gate, newx, newy, newz, rate);
                    GateOpen = 1;
               }
               else
               {
                    MoveObject(Gate, originalx, originaly, originalz, rate);
                    GateOpen = 0;
               }
          }
          else
          {
               SendClientMessage(playerid, color, "Command Not available.");
          }
     }
     else
     {
          SendClientMessage(playerid, color, "You are not in range of the gate.");
     }
     return 1;
}