H1b after 6th year

[Sdh1b]

My h1b extension is valid till May2019(5yr 11months) and perm has been initiated few months back and in progress. If I get perm approved by May and apply I140 in premium  from going back to India and apply extn for 7 th yr from India and post approval I plsn return to usa. My query is do I still need to wait for 365 days of perm application date or before that also I am eligible to return. 

[rara5]

You only have to wait 365 days to file for a 1-year extension if your PERM is still pending and not approved. 

As soon as your I-140 gets approved you can file for a 3-year extension and on approval can return back.