When I installed Lightroom 6 , I did not include my previous catalogues, I made a separate Lr6 catalogue for trail purposes . When I used Import from another Catalogue Light room included all the photos from the pervious versions but did not include all the Dates, Sites, and folder names that the pervious catalogues had. 1200 photos and no designated folders. Did I uses the wrong process and is there a fix other than deleting all the previous imports and asking for help .
The best thing to do is open those other catalogs using LR 6. It will prompt you to create an updated copy, and everything will be there as it was previously. I'm not sure what happened in your import from another catalog process.
Sounds like you used File->Import and not File->Import from Another Catalog.
Are you 100% sure you used File->Import from Another Catalog?
I'm not much of an expert on database formats. But what puzzles me is how they imported from an older catalog without first converting it. Something doesn't seem to add up in my thinking.