My OPT is about to expire on 10/8/.My H1B result is pending.Can i continue to work?

I know about CAP-GAP but what about after 10/1/16. Can i continue to work even after 10/8/16(OPT expiry date)?My employer is not willing to go for premium upgrade

You can work until OPT expiration date if the same is after Oct 1. After that, you cannot work and need to stop working. It may be better to upgrade your petition to PP (you can also pay for it). Maybe have the employer talk to your attorney to make them understand the benefits on PP in your case.