The registration of nominees in the ICICI demat account is an offline process. It cannot be done online. You will have to download a nomination application form, fill it, sign it and submit it to the bank.
Steps to update nominee to ICICI demat account
Download the FORM FOR NOMINATION/ CANCELLATION OF NOMINATION
Print, fill and sign the form.
Attach Copy of any proof of identity like PAN, Driving License of Nominee (major) or of guardian (if minor) is required. It needs to be self-attested and to be attested by the respective authority.
Submit it to any ICICI bank or send it to the address provided in the form.
Note:
Nominations can be made only by account holders. In the case of the joint account, all account holders will sign the nomination form.
Both major or minor nominees can be nominated.
Up to 3 nominees can be added in a demat account. In the case of multiple nominees, the percentage of share for each nominee must be filled that shall total up to 100%. In the event of non-indication of any percentage share, the claims will be settled equally amongst all the nominees.