Yeah i tried from Element.Location. Its taking curve start and end points. Also im getting curve length
How can insert hanger family over duct as an array. say at an interval of 4meter distance
New topic is already here 
: 
https://forum.dynamobim.com/t/to-make-suitable-change-in-dimension-in-penetration-sleeves-with-respect-to-duct-size/32120/3