LEM Report on Severity >= 6

The easiest way to do what you want is to take an existing report, filter it, and then save that as a custom report. In this case, I'd use the "Console - Overview" report.

1. Select the Console - Overview report in the list
2. Click Run and pick a sample date range (can be short, but ideally would have severity 5+ things in it so you could search)
3. Click Select Expert and add your Severity >=5 criteria
   1. Click New...
   2. Choose genericalert.severity
   3. Choose "is greater than or equal to" and fill in or select 5
   4. Click OK
4. Click Export Report
5. Choose Crystal Reports (RPT) and Disk file, then click OK
6. Navigate to Program Files (x86 if 64-bit)\SolarWinds Log and Event Manager Reports\CustomReports
7. Save your report there as an RPT

To run the pre-filtered report:

1. Go back to Settings
2. Click Category > Custom Reports on the right
3. Hit the "refresh report list" button on the top in the Quick Launch, or hit F5
4. Click your Report (it'll be called "Console - Overview" and will show the file path from step 7 above)
5. Click Run

Hope that helps.