Can i convert XmlDocument to TextAsset at Runtime?

When i place a .xml file into project it will automatically convert it to TextAsset file but can i convert .xml file to TextAsset at runtime? or on build version?

An xml file is text. You would load it with System.IO (stand alone) or WWW (web player). In either case you have read the text of the xml file. You can then feed that to an XML parser.