public class Siren : MonoBehaviour
{
    [SerializeField] Texture[] textures;
    [SerializeField] Light[] lights;
    [SerializeField] new Renderer renderer;
    [SerializeField] float delay = 0.25f;

    int currentLightId = 0;

    private void Start()
    {
        StartCoroutine(SirenWork());
    }

    IEnumerator SirenWork()
    {
        while (true)
        {
            lights[currentLightId].intensity = 0f;

            currentLightId++;

            if (currentLightId >= textures.Length)
                currentLightId = 0;

            renderer.material.SetTexture("_EmissionMap", textures[currentLightId]);
            lights[currentLightId].intensity = 1f;

            yield return new WaitForSeconds(delay);
        }
    }
}