This is for all those people with same question

Calculate the period between your kids/ wife's departure and the re-entry to Qatar / or expiry or resident visa ( whichever is earlier )

if the period is more than 6 months, you have to pay QR.500 at the ariport immigartion, before she leaves the homecountry.

the person HAS TO RE-ENTER, befor the expiry of visa.

this facility is given only once ( for 6 months )....before 12 months they have to re-enter