Yes. You can change your Study Centre after selecting one already and you also can select a study centre which is not of your district. There are no steadfast rules when it comes to study centres. The concept of Open School is to let  you study from your comfort zone. You can reach out to the Current study centre administrator and ask the process of changing the study centre, They will help you with the same. You can reach out to the helpdesk at: 1800-180-9393. Its their toll free no#. Try reaching out to them if you have already registered with a particular study centre. But if you want to select a different study centre for the first time, you can use this link to locate the study centre for you and go ahead with it. https://sdmis.nios.ac.in/registration/locate-study-center