GST Applicablity

If a service IT firm :"ABC" who is a start up 1Yr 6 months old with turnover less than 3 lacs plans to start a ecommerce portal by name www.xyz.com for apparels.As per GST norms ecommerce has to register under GST irrespective of turnover.which can be done online.

So how GST registration would be done under ABC company (who has a bank current account )with www.xyz.com as brand name portal and link ABC account for payment collection on www.xyz.com website