Hi Mayur,
Thanks for your interest! There is no upsell feature built into the Event Tickets Plus plugin itself. However, I suspect that some of the e-commerce solutions that run alongside it do have some kind of upsell feature, either included or as a paid extension.
For example, if you use WooCommerce then each ticket is also a WooCommerce Product. WooCommerce has many extensions available, and if they have one that allows you to upsell other products during check out,that could potentially be integrated with our ticketing plugin. Does that answer your question?
Best,
Leah