Is the visit Visa for one month or is it a family Visiti for 6 months. if it a family visit for 6 months u can extend it. for that:

1. your brother should goto Medical and get the Medical clearance.

2. After Medical clearance can goto garaffa imigration and extend it for 1 or for nother 5 months.

The documents needed are:

1. Passport
2. Visa Extension form
(There is a typing section in the imigration,
give ur ID,Passport so they wiul fill it for u or,
goto moi.gov.qa and fill the form if u good in arabic)
3. Electronic Money card (e-cash/Credit/Visa)
4. 200QR for each month

If ur brother have a 1 month Visa,

1. Take the return ticket with the extended date.
2. fill the aplication form
3. talk to the lady who process ur application in garaffa imigration. she wil guide u to talk to one captain in the imigration. If u have luck u may get extention.

All the best. hope this wil help u.