Can we use other assets from outside like from epic or the assets will be provided 

from the Jam’s itch.io page

Assets - Use only assets you have permission for (your own, free, or purchased). If you didn’t create it, you must list it in your submission

You got the right answer, but just to confirm, you can use outside assets as long as you have permission to use them. We will have some freebies you can grab and use for the jam or use at another time according to the asset creator's license.