Your licence entitles you to upgrade to the latest version released before the end-date on the licences. So if your licence is currently valid, you can upgrade now. There's no cost.
You need to be very clear about versions though because you can't have "JIRA software 6.1.7"
I suspect you have one of these two:
Atlassian Summit is an excellent opportunity for in-person support, training, and networking.Learn more
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