No, the GST portal is not yet enabled to accept GSTR 1 of August, September, and October. It will be enabled only after all the returns for July has been filed.
GSTR 1 filing not supported in portal. Wait on further availability...
Also no more restriction for anyone return complete and file next month returns... You can file one by one yourself Upto October on or before 31st December if your turn over above 1.5cr...