Go to event edit page where you want to add Variation and options.

Enable tickets on the ticket and save event post

Once event tickets are enabled on the event, enable ticket variations & options

Before you can start adding variations, create variation types. Once variation types have been created, you can add ticket variations.

You can also add ticket price options from here.

More Documentation: http://docs.myeventon.com/documentation/addons/variations-options/

Requirements: EventON and Tickets Addon