I have lost my ID card so plz tell me how I get my ID card gain

Hii Salma!
Sorry dear, but you haven't mentioned the details about the institute or any id proof which is lost. Your question seems incomplete. If it a school id card or a college id card you can contact to the respective authorities and they can help.you find it or may re- issue a new I'd card. Kindly restructure your question in order to get more details. Hope you understand.
Good luck!