Congrats. once you got the family visa meens you should elegible for call your family to stay in Qatar. now your problem is you son side visa application is rejected. ok

1. can you check once again your son passport isit your name and your suppose name is clear and compare to the application.

2. Are you enclosed your Son's Birth certificate to the application.

3. Please check your son's passport validity time.(minimum 6 months is required)

4. Your son's passport address and your passport adress are to be same (if not atlest your wife passport adress also be same).

5. your son's Birth certificate should be attested by your Nationality Embacy and Qatar Embacy.

For my knowledge these are points where checking in the officer.

please goto your typing center and ask them. All the best my friend.