Legal Question in Banking Law in Illinois

You have no right to claim any portion of it unless you are, for example, a named beneficiary of the account (most IRA accounts allow the owner to name beneficiaries in case of death), in which case you will have to provide the financial institution holding the funds proper paperwork to release it to you (which could include opening of a probate estate), or you are a creditor of the deceased who as a creditor could then open a probate estate and potentially get a court order of distribution to you. But then you may be responsible for administering the estate, including notifying all heirs, etc., and distributing the remainder of it, if any, to the rightful heirs after paying for estate debts, taxes, your claim, other claims if any, etc.

Otherwise, it doesn't matter where the relatives are; they are entitle to inherit, not you, and if others are named as beneficiaries, they would be entitled, not you.

I will say, however, that if nobody notifies the institution of the death, there are no beneficiaries or nobody notifies them, and/or no probate estate is opened and enough time passes, eventually the institution will have to declare the funds on account as abandoned and unclaimed, report it and send it to the Illinois State Treasurer, who will hold it under the "CASH DASH" program for a period of time, and then grab it under the theory of "escheat".

Finally, you don't even say if there was a will, so all the above may be moot if there was one and no beneficiaries were named in the IRA account.