H1B Approved Petition Expiry

[kubsrinivas]

Hi,
My H1B Approved Petition Expiry date is 30-Sept-2017 and have not gone for Stamping till now.
So, is there a possibility that I can go for extension of Approved Petition and then go for Stamping.
If so, when can I go for extension of Approved Petition?
When I can go for stamping?
What is total time is takes for Approved Petition and then Stamping.
Petition Extension and Stamping will be taken care by the Employer and my employer is now ready for both immediately now.

Thanks, please share some comments at the earliest...