Realtors can only be paid by their brokers. You cannot pay a Realtor directly.
That being said, if you have bad credit and you need a rental, you might be able to do it if you can do one of the following: prepay the entire lease, or put a substantial amount down on the lease in addition to the security deposit. That money can be designated as payment for the last 3-6 months and is held in escrow. If you default, the landlord has a cushion.
If you cannot do either of the above, I would recommend you try to rent by owner. Most of the owners do not have access to run your credit and you might be able to get by without a credit check. Check your local newspapers.