Hi Shakil,
EXOS currently doesn't support an option to automatically re-enable accounts based on a timer.
The command you have described is the closest match to what you're trying to accomplish.
configure account [ all | name] password-policy lockout-on-login-failures [ on | off]
You can configure the maximum number of failed logins before a session is terminated (except via SSH).
configure cli max-failed-logins num-of-loginsTo re-enable an account that has been locked out, an administrator must login and use this command.
clear account [ all | name] lockoutIf you'd like to submit a feature request to enable time-based unlock, I ask that you contact your local SE.
-Drew