how should i update a Jira ticket's comment column automatically when ever a build is triggered in Jenkins.???

[Niclas Sandstroem]

There is plenty of materials on this subject. Please see https://blog.dominikschadow.de/2012/07/integrating-jenkins-build-results-into-jira-issues/

One way would be to utilize a plugin like https://marketplace.atlassian.com/plugins/com.marvelution.jira.plugins.jenkins/server/overview to get a more slick/easier integration.