how to rotate object in specific axis

Hi, how can i rotate an object in specific axis for example just rotate it left or right. Normally i just make vector y axis same as objects axis that will be rotated but just changing rotation of x and z axis should work but it doesnt work.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class tankFire : MonoBehaviour
{
    public float soundVolume;
    public AudioClip fireSound;
    public AudioSource mySource;

    public float projectileSpeed;
    public float projectileSize;

    public GameObject fireSmoke;
    public GameObject projectile;
    public GameObject fireFire;

    public Transform turretPivot;
    public Transform gunPivot;
    public Transform projectileLoc;

    public float baseTimer;
    public float timer;
    public float turretRotationRange;
    public Transform enemy;
    Quaternion targetRotation;
    Vector3 targetDirection;
    void Start()
    {
        mySettings.effectVolume = 1f;
    }

    // Update is called once per frame
    void Update()
    {
        if (Input.GetKeyDown(KeyCode.K)) fire();
        rotateTurret();
    }


    void rotateTurret()
    {
        targetDirection = enemy.position - gunPivot.position;
        targetRotation = Quaternion.LookRotation(targetDirection);
        Quaternion gunRotation = targetRotation;
        gunRotation = Quaternion.Euler(0f, gunRotation.eulerAngles.y, 0f);
        float angle = Quaternion.Angle(transform.rotation, targetRotation);
        timer += Time.deltaTime;
        //if (angle > turretRotationRange) return;

        gunPivot.rotation = Quaternion.Lerp(gunPivot.rotation, gunRotation, 5f * Time.deltaTime);
    }

    void calculateTimer()
    {
        timer += Time.deltaTime;
        if (timer >= baseTimer)
        {
            fire();
            timer = 0f;
        }
    }
    void fire()
    {
        mySource.PlayOneShot(fireSound, soundVolume * mySettings.effectVolume);
        GameObject currentBullet = Instantiate(projectile, projectileLoc.position, targetRotation);
        currentBullet.transform.localScale *= projectileSize;
        currentBullet.GetComponent<Rigidbody>().velocity = targetDirection.normalized * projectileSpeed;
        Instantiate(fireSmoke, projectileLoc.position, targetRotation);
    }
}

my bad its working there was 2 same script thats why it wasnt working