position

var para=app.activeDocument.textFrames[0].paragraphs[0];
var pos=para.paragraphAttributes.tabStops[0].position;
alert(pos);
// タブ位置の設定
var tabList=[];
tabList[0]=new TabStopInfo;
tabList[0].position=100;    // pt
tabList[0].alignment=TabStopAlignment.Left;
tabList[0].decimalCharacter="-";
para.tabStops=tabList;