Hi Abhishek,
It would be best if you could post your question in the Cisco Support Forums and check.
https://supportforums.cisco.com/community/netpro/security/vpn
This issue could arise if the User is behind a Firewall or if the TCP port that the VPN client is blocked.
As a work around, I would suggest you to disable the Windows Firewall and check if it makes a difference.
Note: Once done troubleshooting, turn on the firewall.
Let us know if this work around helps.