hi kabayan, if the case is like this , you need to apply new visa since he didnt return here for 6 months but when you apply visa, you need to attach his old iqama (copy) and all pertaining Documents required and this is to be done in labor department! it will quite easy because he has already record in labor dept. and his residency ID # will be the same with the old. im telling you this because you have similar case with my daughter.

hope it will help..