H1B extension period after visa validity

Hi Saurabh,

1)My H1B visa was stamped only for 10 months and is expiring on 16 Dec2013. And due to some personal reasons, I’m not able to travel to USA till end of this year 2013 . S0 is it possible to get the extension done in India itself without travelling to USA once.
2)And if it can be extended in India then how long it may take for the extension process.
3)Also please let me know the period for H1B extension after the expiry of visa(within month of visa expiry or do we have some more grace period?)
Please do the needful.
Thanks in advance.

Thanks and Regards,