same business with Sub dealer

Hi
We have started Okinawa electric Scooters business. here Okinawa company will give License to operate main dealer, but main dealer can give Sub dealer ship to others and all invoice should made by main dealer only & GST return done by main dealer only. But as per consultant subdealer no need to register for GST.
How does it work. it means there is nothing proof for amount transaction which is happened in subdealer account. buying and selling
what is the solution.
and for RTO registration happens only from main dealer office not from subdealer because the license will be in main dealer name.

please help someone