Tickera works with any well coded WordPress theme. It follows the styling of a theme and blends its content to your website as seamless as possible.
Good place to start your search is a selection of event-based themes we are affiliated with and which can be found here. Of course, if you fail to find anything that suits your needs there, you can continue your search on some of many online theme markets (i.e. ThemeForest, Templatemonster, MOJO Marketplace, etc.) or use some of the free themes from WordPress' own theme repository.
However, since Tickera has a seamless integration with WooCommerce via our Bridge for WooCommerce add-on, if you intend on using it that way, make sure that the theme in that case must declare WooCommerce compatibility since WooCommerce has some special theme requirements.
So, basically, the short answer is quite simple; with Tickera you can use any theme you see fit for your particular needs and that matches your personal preferences and taste.