As per the GCC law if any person out of country for more than six months his RP will get expired, but at ur case no problem becaude ur childern is studing there but recent amendment on family RP, u can request the immigration ( immigration office near air port)to extend another six months ,u will pay about 500 QR/CHILD, and make photo copies for there passports and ur passbort also the RP valid for another six months els till the valid period paying some additional fees. Good luck