H1B extension after travel back to india

USA H1B Visa
1

Hi,

My visa validity is till Dec 2015 and i am going back to india in a week. (stayed only for 3 months in H1)

Can my employer extend the visa after i go back or they have to file a new petition under cap exempt?

Also is this can be done after my visa expired?

Thanks

2

I think they can simply extend the visa. And I am not 100% sure but I think extension can happen after the expiration as well.