I'm not sure I understand. Do you want support for JIRA OnDemand or for Gantt in JIRA OnDemand?
You can get support for JIRA OnDemand at jira.atlassian.net selecting 'OnDemand'.
If you mean Gantt, there is this plugin for OnDemand. It is not supported by Atlassian, but you can use it in OnDemand and get support with the vendor if you need.
Jaime Kirch da Silveira
Badges are a great way to show off community activity, whether you’re a newbie or a Champion.Learn more
Trello is one of the most effective tools for driving your sprints. It's customizable for every Agile team and product owners and Scrum masters (SM) love it. However, Agile teams often struggle with:...
Connect with like-minded Atlassian users at free events near you!Find a group
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no AUG chapters near you at the moment.Start an AUG
You're one step closer to meeting fellow Atlassian users at your local meet up. Learn more about AUGs