after login in Unified Portal of employer, just copy and paste the link i have funished in the reply, it will open page for filling the branch details, fill the same properly and submit, if you feel any issue there is specific help file provided by EPFO
When an establishment opt to do business under same PAN identity / management i.e branches of business, at different places within india, and pay the EPFO, they have to either maintain it centrally i.e at headoffice or opt for branch wise / location wise with sub coedes, they have to fill the form2 online properly and submit, on sucessful submission department will communicate the principal via mail