Petition approved but need to file amendment

[waitingapproval]

Hi,

I am in India and my H1 petition is approved for this year but the project and location for which it is filed will change as I am moving to different project by year end.
But I can still go for stamping from the current project as project will be there for some more time.
The Question is should the amendment be filed before stamping or after stamping. Please any suggestion or advise.

Regards