Is it illegal to use culture symbols on t-shirts and sell them under the clothing line name?

This question is ultimately, is there a registered or unregistered trademark which I would be infringing upon if I put this symbol on a t-shirt? The answer to this question would require a search do by an attorney who is looking at relevant symbols in use trying to determine if your intended use would cause confusion in the marketplace with a symbol already registered or in use.

Using an ankh symbol. like using a peace symbol, is probably not a violation of trademark or copyright as long as your exact design does not violate anyone else's trademark or copyright. It probably won't if it is an original design. But when you have questions like this, it is a good idea to consult with a lawyer and show her your exact design and what exactly you plan to do.

Items/symbols that are ancient in age falls under public domain and you are able to use them. note, however, that others will be able to use them as well.