Reddit doesn't do hard IP bans, but they do a lot of fingerprinting to link alt accounts together and will ban them all. You can get around it but you have to be pretty careful, wiping cookies on all your devices, signing up from a new IP, never logging in to the old accounts again, etc.
Regardless ban evasion is always forbidden so if you slip up or get caught because of the way you type or whatever, you will be banned again.