Hi Ashok,
You have multiple options for the reporting of VPN clients.
You can opt for local or remote logging.
Please check these links:
https://supportforums.cisco.com/discussion/11271861/question-how-log-anyconnect-sessions-syslog
https://supportforums.cisco.com/discussion/11745731/anyconnect-session-accounting-radius-or-syslog
Regards,
Aditya
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