How to Display particular No.of Images in Jetpack Tiled Mosaic Gallery

I have posted many no.of images in custom post type, It display all the image in front, But i want to show only six images (see below screen shot) in front display all the images using carousel,

For Example:

Post 1 can have 10 images but i want to display 6 images in front

Post 2 can have 18 images but i want to display 6 images in front