Where is this realtor David Atkind and why did he surrender its realty licence: cuz it is needed for my Writ to execute?

Realtors are NOT licensed by the state. Brokers and salespersons are licensed by the state. Realtor is a trademark of the National Association of Realtors. Only a broker who joins the NAR can use the name Realtor. The state has NO involvement in that. The state can revoke a broker's license, and the NAR would immediately deem that person as no longer having the right to use the trademark. There IS no Realtor's license.

To get information on any former licensed individual, you first contact the local real estate board the individual was connected with. They may give you the last mailing address on record for that individual, but anything to do with why a license was surrendered will NOT be given to you. For that, you will have to contact the state department that issues real estate licenses. In New York, it's the Department of State. Other states, I don't know.

If you cannot locate the person using these sources, you may have to hire a private investigator, and then you'll have to pay a process server.

Call the Association of Realtors in your area and explain your problem.

Realtors are licensed by each state. Contact the state agency that regulates the real estate profession.

Contact your local branch of the state real estate board and ask them how to locate him. If you have to serve someone, hire a process server. That's their job.