For example, issue CRM-17493 shows that it is fixed in 4.6.11.
How do I find the patch to fix this specific issue from JIRA?
That patch is due to be released in CiviCRM 4.6.11 but it hasn't been released yet. 4.6.10 is the latest version of CiviCRM.
You can download the latest version from here: Download CiviCRM
How to apply a patch: How do I apply a patch supplied in the issue queue via Git?
This is a little tangential, but there are several options for checking an unreleased patch: