As far as I'm aware only spouses and children of the visa holder are eligible for a family visa. Your parents might be eligible for another visa, though – please see Visas for Oman for more.
Hi, I assume you're on an employment visa? How old is your son? If he's under 21, you can bring him over by getting a family-joining visa. You can find more info on the Visas for Oman page (link).
As far as I'm aware only spouses and children of the visa holder are eligible for a family visa. Your parents might be eligible for another visa, though – please see Visas for Oman for more.
Meagan