You can actually nominate someone as the beneficiary of your demat account. Actually, it is always advisable to appoint someone as the nominee of your demat account as the identification of beneficiary and transmission becomes automatic in that case. Say Jayant is holding a demat account in his name and is holding shares worth Rs.50 lakh. He does not have a joint account and does not have a nominee. If he were to suddenly die then the children will have to go through a very lengthy process to transmit the shares into their account. If it is nomination then the transmission process is very simple. You just need a certified copy of the death certificate as proof. Nothing else is required if the nomination is done.
Nowadays nomination is mandatory. If you don’t want to appoint nominee then you need to mention it clearly and say that you do not want to nominate. You can also nominate multiple names like 3 or 4 people to be nominees. You can set up the percentage distribution also. If you don’t distribute like percentages then it is automatically equal for all nominees. Remember you can only nominate entire account. You can have nominees for individual stocks or specific ISINs. That is not permitted.