Need help on back dated approval cases:

[Manevikas]

In my case my extension is filed on 3 rd June with SoW valid till 31st October, last month My employer upgraded it to premium to avoid the backdated approval, but I received RFE, so now this might take time I still don’t have RFE details and in this case I might get backdated approval only. So i have some questions 
1) do I have to leave immediately upon getting backdated approval - do I get to use 240 days or I have to leave immediately my 240 days will be over by feb 2020.
2) do we get to file next extension from here or I have to do it from India. And in such cases how much time it takes including stamping.

3) can we provide new SoW with the RFE response and does USCIS accept that? I heard they won’t accept anything other than RFE response only?

Any help of above is appreciated and This will help me in being ready 

Thanks in Advance.

Edited October 10, 2019 by Manevikas

[Manevikas]

16 minutes ago, Manevikas said:

In my case my extension is filed on 3 rd June with SoW valid till 31st October, last month My employer upgraded it to premium to avoid the backdated approval, but I received RFE, so now this might take time I still don’t have RFE details and in this case I might get backdated approval only. So i have some questions 
1) do I have to leave immediately upon getting backdated approval - do I get to use 240 days or I have to leave immediately my 240 days will be over by feb 2020.
2) do we get to file next extension from here or I have to do it from India. And in such cases how much time it takes including stamping.

3) can we provide new SoW with the RFE response and does USCIS accept that? I heard they won’t accept anything other than RFE response only?

Any help of above is appreciated and This will help me in being ready 

Thanks in Advance.