HI..Im from SL too. You can get tourist visa for your family for two weeks and you can extend that for further two weeks. So after that they will have to go back and come again.

After you get your RP, you can sponser your family. If you are trying to get tourist visa for your family you have to come here first and find a cheap hotel which will arrange visa for your family. You cannot get visa from Sri Lanka coz they dont stamp visa from SL.