Maybe you could state what the problem is and you could get some free help here.
I upgraded from LR 4 to 6 and the first thing that happened was I lost key
words for 10,000 photos
Did you convert your LR 4 catalog to work with LR 6? It is almost automatic when opening LR 6 for the first time. But can be done manually after the fact.
Or did you start a new catalog and import all your images into LR 6?