Once you have secured family visa:
On-Arrival Visa, Visit Visa or Tourist Visa

All above type of visas, can be changed to the RP without exiting Qatar.

You need to go to Gharafah Immigration Service center

Building 1 - Ground Floor

First, go to the main reception, tell them your family is already here on visit visa and you need to convert this to family visa.

He will send you to the first room beside the reception on his left.

The officer will make the change of visa on his computer, it won't take more than few mins. afterwards he will ask you to take the token from reception and goto the service counters to pay the fee of 500/passport. ( this saves you from exiting the Qatar which will probably be double in charges.

Remember to print a copy of your new visa, original passport and ATM card to pay at the reception.

I learnt this the hard way, running between gate 1, gate 2, 2nd floor, different receptions etc etc, this might help someone.

Good Luck

https://www.google.com/search?q=gharafa+immigration+office+timings&rlz=1...