As you are an Engineer by profession I assume that you will not be having a visa of a low income employee. As Sonia asked, what is your profession in your visa? You should be a good salaried person who will be able to look after your family decently. The minimum salary bracket I think is Qr. 7000/- for applying the family visa and a person who can get a salary of Qr. 7000/- will not be a driver or a labourer.