JIRA Administrator is disable for me. Please tell me the way I can enable the same

[Nic Brough -Adaptavist-]

There are three types of "administrator"

1.  System admin (can do any admin action in JIRA)
2. JIRA admin (has application admin only, cannot do system level stuff)
3. Project admin (can admin a project)

In all cases, you need someone of the same or higher level to add you to the groups or roles that grant you admin.

Note that you do not get System Admin level on Cloud installations.

Or, have I misunderstood the question?