Restricted cash may or may not be a current asset depending on how long it will be restricted for.
Current assets are any assets that will provide an economic benefit for or within one year. Restricted cash is any cash that is set aside by a company to be used for some purpose at a later date. If the cash will be spent within one year, it is a current asset. If the cash will be unavailable for longer than one year, it is a non-current asset.