@arqumjan the fbr site for public access is updated every thursday. However the data is updated every day at 4 AM for Internal FBR access. - Every return submitted immediately generates an acknowledgement electronically, that contains your details plus the NTN number. That receipt is enough and can be used as evidence of being a Tax payer.
i suggest ask for acknowledgement receipt from your tax lawyer every month. if you are also registered at Sales tax & provincial revenue - both departments 'by law' require submission of monthly tax return in any case ' acivity or nil' - and generates a receipt free of charge to be printed & stored by the tax payer for own records.