Q:

Can i submit ipad app on appstore only with landscape orientation?

App is a just eat type of application for ordering food.

A:

Apple doesn't put any restrictions on specific orientation. It is purely dependent on the App requirement & flow. 
So doesn't matter if Application is for only with Landscape orientation or only with Portrait applications.
If it is according to the apple guidelines than they will approve it. Doesn't matter which orientation App supports.

