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.