you confused some of your reader with your question, anyway i understand that you want to call your sister in law. yes you can call your sister in law with two ways first you sponsor her but you need to submit your and wife valid resident permit passport copy along with your marriage certificate. other same papers you needed if your wife going to sponsor but for this she needs to be appear infront of captain to prove it that she having blood relations. furthermore, you get 14 days qatar airways visa which extend more 14 days for this you apply on airport immigration, while for six months you need to apply in main immigration office located in madinat khalifa. for six month be assure your visitors must need to visit abu humour medical commission for medical which cost same 100 riyal and for six month you need to pay extendable fee worth of 1000 riyal to immigration office as at the time of landing immigration cabins only stamp for one month (incase of six month visit) further if you want to know you may call me on 5493988.