Nutanix unified storage (files)

Hi,
your best option will be nutanix move, 
if your data on unity is on top of NFS/SMB, you can use move to migrate it off of it to nutanix file server.
have a look at below guide 
Nutanix Files Migration Guide

Thanks for your reply ,

Move will migrate all files with the permission ?

what about the performance if migrate one folder contains folders and files 18T , recommended files standard or distributed ?  

Depending on the type of shares you will choose standard or distributed. 

Distributed is best suited for home directories, user profiles and application folders. 

Yes, move will migrate ntfs rights as well.