I have a nexus switch connected to ISE. But the current configuration on the switch has all the AAA configured on it. Is there a way that if someone logs on via ISE (AD), there is a policy pushed from ISE to the Nexus to give the user privilege level 15
Cisco Nexus devices are capable of having AAA functionality supported via LDAP. According to Cisco documentation, Nexus switches support Active Directory as an LDAP server, so yes, it is possible to have AAA configured on the switch with an AD policy being pushed to the switch for access.
I hope this has been helpful!