Im working on work visa under the company sponsorship. Pls help me how can i get my wife and kid for three months visit to qatar?

Bcz my basic salary is 2000 QR per month, but im getting more then 3000 QR as commission.

Is it possible to get my wife and kid by showing 2000 QR salary certificate? Bcz If i request the salary certificate the company will give me on my basic salary.

Then what are the documents i need for the visit visa...?