It's not against the rules to have more than one account on one IP, it is against the rules to have more than one person on an account.
Note that when there is more than one account on an IP, what happens to one account will happen to the other. (For example if your brother scammed a user and you were on the same IP, your account would get locked as well)
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I'm on a different IP address
That's fine, just remember that it's one account per person, not per IP.
DO NOT ever use some elses account in the future, even if it is your brothers.