Can I reuse the same H1 CAP, after cooling period of 1 year outside US?

[RAA]

I have stayed in the US for 5 year 10 months, on H1B+ L1 visa (5 years on L1 and 1 year on H1---total 5.10 years), however I got the visa stamped until September 2015 (not sure what went wrong, USCIS gave 1 additional year), but as it was illegal to stay beyond the 6 year period, I left the US on May 2014 (Would have completed 6 year period in July 2014 but left early due to certain circumstances) with my family.

I will be complete 1 year out of country this May 2015. My question is, can I re-enter US with the same H1B CAP as it is valid till sept 2015 and file for an extension (provided july 2015 - sept 2015 is enough to file the extension) or Will I have to wait till next april 2016 to apply for a fresh H1B visa.