>1) Does Meraki MX appliance have Cisco ISE functionalities? If yes, is there any license which needs to be procured for it? If no, is there any Meraki box which has those funactionalities?
You need the normal Cisco ISE licences. Meraki will do out of the box a lot of what you can do with ISE. Depending on your needs you may need to add in an external RADIUS server like Microsoft NPS or even FreeRADIUS.
>2) Do the Meraki MR boxes need to be integrated with any identity access control device for AAA management?
If you want to use per-user authentication at scale such as WPA2-Enterprise mode, then yes. If you are not doing user authentication (such as guest portal) then no.