I just made this account (litterally a few minutes ago) and haven't gained anything on it. It used to ask what kind of account you wish to make, but this option I couldn't find anywhere. Now the game logged me in as normal account, while I wanted it to be a HCIM.
Is it possible to convert this somewhere by a jmod, as the account hasn't been played on at all yet?
If you don't choose the account type (Ironman) during the character creation (RS3) or in Tutorial Island (OSRS), then there is no other way to make that happen. You have two choices: either make another account and make sure that you do indeed select the type before fully creating it or go through the full account deletion process. This process takes up to three months but will ultimately allow you to use the same log in again for another account.