This is all I did to get mine working on windows 10 http://itthatshouldjustwork.blogspot.com/2015/07/cisco-64-bit-vpn-client-on-windows-10.html

There is not an up to date client, Cisco VPN is EOL'd It was replaced with Cisco AnyConnect

@sreekumarpg said:

Thanks all.

It was a miss configuration in Remote Access VPN Group Policy.

I have added local DNS and external DNS (google DNS) in the group policy DNS Server , then Inherit the DNS names in Split Tunneling and disable send all DNS lookups through Tunnel .

Now the nslookup work like charm in any connect vpn 😃

Glad it was fixed!