I don't know of a way to import users from NT to the ACS, but it may not be necessary. You can configure Cisco Secure to use NT as an external database. All you have to do is go to the External Database section of Cisco Secure and enter NT. Then, in the group setup area, set up the group that your users are in to authenticate using NT, or maybe external database (I don't have the information in front of me).
That may not be what you want, but it may be a quicker way for you.
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...