do we need an attorney to filed
Try to be more clear, what is NLRB? Also, as a general rule: if you think you might need an attorney, it is best to get one.
Nothing discussed should be taken as legal advice. Posting details of your case on an open forum could be used against you, so use extreme caution. The best way to get legal advice is to consult privately with an attorney.
Employment / Labor Attorney
You can file a complaint with or without an attorney at your regional NLRB office. However, it would likely be very helpful to you and your case if you seek the assistance of an attorney. You can search for an attorney with Labor experience on Avvo or contact the National Employment Lawyers Association or your local bar association for a referral.
This answer is provided for guidance only. DO NOT rely on it as legal advice. We DO NOT have an attorney-client relationship. You should contact an attorney in your area for a one-on-one consultation before pursuing any action or making any decisions.