Is it possible to have a few tenants in DB: some tenants data encrypted (TDE) some not encrypted?
No. Encryption is defined at the table/index level and not at the tenant level.
It you encrypt a table or index, it is encrypted for all tenants
I see. Thanks a lot, Richard.
Yes and although you can add encryption policies at the area level, this is only applicable for Type I areas, not Type II areas and of course your tenant data must be in a type II area..