In my org, we are using Anyconnect IPsec-IKEv2 for all remote users and now we have to plan to have this integrated with DUO or Azure AD. So wanted to check whether with IKEv2, will it work or should I need to enable SSL as well ?
Yes that will work. You don't necessarily need to enable SSL (TLS), but if you do ensure you are using TLS 1.2 and DTLS 1.2. Make sure you use the latest AnyConnect version to get the best performance.