if condition false also it is redirecting to sign up page can any one help in this

public IActionResult Index()
`enter code here` {
    HttpContext.Session.SetString("Tenant", _tenant?.ToString() ?? String.Empty);
    var tenant = HttpContext.Session.GetString("Tenant");
    if (new Guid(tenant) == new Guid())
    {
        return RedirectToAction("SignUp", "Register");
    }
    else
    {
        return RedirectToAction("SignIn", "Register");
    }
}