Hi mahesh213,

Refer below code.

Model

public class Customers
{
    public int Id { get; set; }
    public string Name { get; set; }
    public string Country { get; set; }
    public int Salary { get; set; }
    public List<Employee> Employees { get; set; }
}

public class Employee
{
    public int Id;
    public string Name;
}

Controller

public class HomeController : Controller
{
    // GET: Home
    public ActionResult Index()
    {
        SaveColumnsAndValuesToDB();
        return View();
    }

    private void SaveColumnsAndValuesToDB()
    {
        List<Employee> employees = new List<Employee>() {
            new Employee(){ Id=1, Name="Emp1" },
            new Employee(){ Id=2, Name="Emp1" }
        };
        Customers customers = new Customers { Employees = employees, Id = 1, Name = "John Hammond", Country = "United States", Salary = 50000 };
        foreach (var prop in customers.GetType().GetProperties())
        {
            string fieldName = string.Empty;
            string value = string.Empty;
            if (prop.PropertyType.IsGenericType)
            {
                List<Employee> employeesData = (List<Employee>)prop.GetValue(customers, null);
                value = string.Join("/", employeesData.Select(x => x.Id).ToArray());
            }
            else
            {
                fieldName = prop.Name;
                value = prop.GetValue(customers, null).ToString();
            }
            string conString = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
            using (SqlConnection con = new SqlConnection(conString))
            {
                using (SqlCommand cmd = new SqlCommand("INSERT INTO Customers VALUES (@oldvalue, @newvalue, @FieldName, @CreatedDate)", con))
                {
                    con.Open();
                    cmd.CommandType = CommandType.Text;
                    cmd.Parameters.AddWithValue("@oldvalue", 0);
                    cmd.Parameters.AddWithValue("@newvalue", value);
                    cmd.Parameters.AddWithValue("@FieldName", fieldName);
                    cmd.Parameters.AddWithValue("@CreatedDate", DateTime.Now);
                    cmd.ExecuteNonQuery();
                    con.Close();
                }
            }
        }
    }
}