The maximum allowed size for a Dropbox file is 100 MB.
You can sync only one Dropbox folder with a Zoho Docs folder, at a time.
As of now we don’t support Dropbox sub-folder syncing. So, sub-folders residing under your Dropbox main folder will not be synced.
We don’t support file deletion sync as yet. You will have to manually delete files in both services i.e Zoho Docs and Dropbox.
We have currently restricted selection of sub-folders for syncing to 10 folders. We are looking into the possibility of increasing the sub-folder limit in a future update. However, there is no restriction on the main folders.