My son is studying in class 12th in qatar and his...

Kindly be noted that you can renew the visa by downloading the renewal form via the following link: -
Visa renewal application  
Then, go to the Passports General Department and submit the required documents:
Valid passport
The visa that is to be renewed
A copy of the ID card
Submit the document state on the visa renewal application
Pay the required fees
Submit your child's birth certificate and previous visa