My OPT expired on June 2012 but before expiration my employer filed H1b. USCIS asked for RFE which was submitted in timely manner. Just today on 11/8/2012 I found out that my petition is denied What are my further options? Can i repeal the petition and what are the chances of approval after repeal?
Yes, you can reappeal and nothing much can be done about it.
Also talk to your DSO about further options as your grace period starts from 11/8/2012.