Not necessarily. Only if you buy from a broker, then you can see them in your demat account. In all other options, you get statements like demat accounts and it can work out completely online, eg. for a particular AMC, you can have an account wherein you can do all types of transactions. From Karvy/CAMS, you can get overall statements of all of your MF based on the PAN. There is no advantage of having MF units as demat.