Stay extension for B2 visa holder

Hi, Is it legal to stay after 6 months while the current B2 visa stay extension is in process (biometric completed in 1st week of August)?

I checked the processing time on
Processing Times and it shows approx 15 months

Current i94 expiry is in October, trying to understand my options, can someone please help?

Yes. You will be considered in authorized period of stay between the I-94 expires and the extension is approved/denied.