How to register multiple attendees at the same time

How to register multiple attendees at the same time

Hi,

I've set up the Registrations add-on, and now attendees could register, but how I can add an option (without modifying code), so the clients could register several persons at the same time?
Will "Sell Tickets" add-on help with that?

So basically I need an option so the client could choose a number of persons they want to register for a particular event and fill information for each attendee. 

Thanks a lot in advance!