How can I select 3 different groups of objects with the same script?

I’ve got 3 lights as child inside 3 different groups. Each of these lights has the same script. And the script determines the behaviour of the lights, which must be the same.

I want to activate the lights of each group depending on certain conditions.

The solution could become from some ways, but one of them is:
I’m thinking about re-tag them, with different tags depending on the group the lights belong to.
Should I create a vector variable of three elements and fill it in some way with the objects tagged with a certain tag defined by me and then apply a for loop for selecting them?.

    var luces_respirar  : GameObject[];
	  luces_respirar  = GameObject.FindGameObjectsWithTag("luz_respirar");
    if(Network.isServer)
{
	if ( (luces_resp_encendidas==true)) {       
       for (var GameObject in luces_respirar) 
            {
            active=true;
            }

	}
}

You can use this script to perform actions on all the children of an object:

for (var child : Transform in transform) {
    child.active = true;
}

http://unity3d.com/support/documentation/ScriptReference/index.Accessing_Other_Game_Objects.html

Or you can use SetActiveRecursively(true) on the parent objects for each set of lights.