In NJ when a seller signs a contract with an agency, is there a "buyer''s remorse" clause within the 1st 24 hours to rescind?

The answer to your question will lie with the specific laws of your state and the specific language of the contract.  I cannot therefore answer your questions without having the benefit of both.  I can tell you that it would be unusual for state law to incorporate a "buyer remorse" concept into a real estate purchase contract.  Your question raises another question, however.  Your question indicates that the seller (which I presume is you) may have signed a contract with an "agency" --- a real estate agency I assume -- and not with a specific buyer.  Is your contract merely a listing contract, or is it a contract to sell the property?  If the former, your agent will be authorized to find a buyer willing to pay the listing price.  If you signed an actual contract of sale with the understanding that the agent will then present it to a buyer, then you have merely made an offer to sell on the terms given in the contract.  You can revoke the offer before anyone has accepted it in writing.  If the question is important to you, I recommend that you confer with a good real estate attorney in your area.  Take the contract (whatever it is that was signed) to him for review.