Until there exist a program that can directly convert CRYPT6 to HTML you have to use a workaround to achieve that. In order to convert the encrypted chats from CRYPT6 archives to HTML, you first need to convert CRYPT6 to CRYPT and then use one of the available CRYPT to HTML conversion tools to encrypt and extract the *.crypt archive and save it as *.html file.
Convert WhatsApp Messenger encrypted message database backup file to HyperText Markup Language web page.
We found one software available in the database for this conversion.
Articles and other information relating to crypt6 into html conversion:
How to convert WhatsApp CRYPT files - Decrypting WhatsApp message databases
On-line services software - convert crypt6 to html on web
Online service for WhatsApp databases
Convert from crypt6 file format
The table with program actions contains information about what each program is capable of doing with their files. This may be a good pointer for further searches for certain file conversions and help you find the converter you are looking for if our search result is insufficient for you. However, it is far from perfect and may sometimes show results which are not really usable because of the nature of the software handles the files. So a conversion that appears as possible, just because of matched actions, may in fact not be possible.