Visit Visa Extension for my Son

Hi,

Does any anyone here can able to suggest me about visa extension for my son? I will summarize the details.

My wife and son arrived in Doha last December 11, 2015 under my sponsorship of Family Visit Visa. They have completed the 6 months stay in Doha last month and able to extend their visa until 7th July.

However, my wife already got a job and presently she is under the sponsor of her new employer which last Thursday her visit visa has been transferred to work visa and hopefully one of these days she will have a medical test..

My problem now is for my son whose visa shall expire next month 7th July, that would be his 7th month stay in Doha.

My question, is there any chance that he might be extended his stay in Doha, he is 4 yrs old.

Or how can I bring him under permanent visa knowing that my salary in only QR6000 plus..

The visa category of my wife now under her new sponsor is Assistant Professor.

Please enlighten me.

Thanks.

William