H1B extension while in India now

Hi, I have H1B visa valid till 7 Dec 2012 ( i got H1B visa for only one year). i have worked at onsite for 4 months (from Mar 12 - Jun 12). I did not file for h1b extension yet. I would like to know if i can file for H1b extension NOW while in India. Kindly let me know how to do it.

Yes, your employer can file with supporting letters.