Out of status during H1B extension

[greatdesi_2]

Hi,
Currently on 6th yr of H1B & PERM process(Green Card) is on process.My visa expires in 4 weeks & planning to apply visa extension in 1 week(as premium processing).Incase If I get RFE in 2 weeks & will get 4-6 weeks duration for responding to the RFE.
Will I be out of status incase my petition is not approved after 4 weeks ?
Or any flexibility to continue the project work if my extension is on pending processing?

Thanks in advance!
Desi Friend