No, it is not mandatory for the guardian to have an account with Jainam in order to open a minor account. However, if the guardian wishes to open an account for themselves, they can do so separately by following the individual account opening process. To know more, see How can I open a demat account with Jainam online?  for offline process, What are the documents required for account opening by any resident individual at Jainam? The guardian can act as a guardian for the minor account even if they don't hold an account with Jainam.