Can I update IPad from iOS 10 to 13.5

It’s going to depend on the model of your iPad and if it can handle iPadOS 13. If it can handle it, then you will be able to update to it. If not, you’ll be able to update to the highest version that your iPad can handle. Go to Settings>General>Software Update and it will show you what you can update to. Your iPad will automatically go to the highest version available that it can run and will not update past that.

To do a software update, fo to settings>General>software update.

You'll see your available, next version, depending on the model of iPad.