Registration has not opened due to a very simple reason: Prior to registration fpsc releases a public announcement in newspapers to invite css aspirants to apply in online registration. Once this advertisement appears in newspaper, only then the registration will begin. This advertisement will contain information about start date and end date of online registration of css 2018 exams.
Hope this removes any confusion

For more details refer to this 29thseptember notice: http://www.fpsc.gov.pk/icms/admin/ne...lic-Notice.pdf