H1B Extension on basis of Perm approved and i140 application

[YBA]

Hi,

I will be completing 6 years with H1B visa in Apr-2018. My perm has been approved. and I140 is currently in process as I have got RFE. 
Can I extend my H1b basis on my I140 In-process status?
I heard I will be eligible for 1 year of extension. Is this possible?

 

[care_candidate]

Taking from my own experience, H1b extesion beyond 6 years is possible only after approval of I-140 not "In-process".

And, it is 3 year extension, not one year.