Gold clusters are known to have size dependent geometries. The study of golden cages of different sizes and dimensions has gained momentum in recent years as they can accommodate guest atoms to form a new kind of endohedral structure. We will be studying the doping of gold tubular cages with transition metal (TM=Ag, Cu and Au). Their geometrical structures, relative stabilities, binding energies and bond lengths are studied using Model Potential approach- Gupta Potential (GP). AuAg and AuCu have been chosen because they may be expected to show different behaviors. As far as our knowledge no such work has been reported earlier. It is observed that doping of Ag and Cu atom at the centre of planar Au6 results in a three dimensional geometry. The atom-atom interaction potential predicts the dominance of the finite size effect as the number of Cu and Ag atoms increases along with the size of gold tubular cage. Copyright © 2018 VBRI Press.