You can try working your way through https://confluence.atlassian.com/display/JIRAKB/Export+More+Than+1000+Results+to+Excel but do bear in mind that the limit is set at 1000 for a reason - large exports can crash out, while destroying the performance of the system. A better approach is to examine why you want the export - in most cases, it's an ill-thought out requirement and there are better options than export and mangle in excel. (Also bear in mind that around 90% of excel sheets are, well, wrong)
I agree with Nic that you first (probably) need to find out what metric you wanted to understand with the help of this report. A raw list of 6000 test cases is not something you can get insights from...
Note: it can also help you to generate a list without further reporting assets (charts, etc.), if that's what you are primarily looking for:
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