hey akshay,
I think you have to wait a bit to be able to use number arrays, as its not implemented yet.
Max wrote about it a couple of days ago in another thread:
http://forum.playcanvas.com/t/new-script-attributes-array-true/2291/2?u=martin
A tmp solution might be to use the string set and convert it into an internal number array in your initialize function.
Greetings,
Martin