@prasoon2211 Being able to define _any_ vector in multiple frames is critical for multibody dynamics problems. Look through the mechanics examples for some examples. 

The challenge here is that position (or other) vectors define the configuration of a new frame can be a sum of vector components in the new frame and in other frames. Hence my suggestion, having the user supply: position=(parent, (v1, v2, v3), other_vec_component). You could simplify the user's input a bit, by allowing position=(parent, (v1, v2, v3)) or position=(parent, other_vec_component) if only part of this is needed.