Hello @Santhakumar,
This error is occurring on the target source and does not require IdentityNow expertise to troubleshoot. Your best course is to find someone who is an Active Directory expert and can help you understand why Active Directory is unwilling to process the request.
I am no expert but doing some quick searches on the internet it appears there might be an issue with the password being set on the account. Active Directory would reject the request if the password does not meet the configured policy.
Cheers!
Blaise