I'm making a homepage template for my theme and I want to call a plugin, namely royalslider. Surely
do_shortcode('[gallery id= "1"]');
Should do the trick?
You should also remove the space after
Finally, make sure that you have images attached to the Post with the ID 1, which is what that shortcode would normally output.
I'd suggest you make your gallery in a post, and then have a post in a featured category, and display that ( with the shortcode in the content ). use a WP_Query loop with a limit of 1 post to prevent interfering with the main loop
This also gives you the extra flexibility of changing your mind or updating the slider, or using a static image, or having a text based feature