You cannot make changes to you application form once the correction window for NEET has been closed. NTA's information Brochure has been clear about that. The merit list is prepared based on the Category you have filled during filling the application form and your NEET score. So the same Category needs to be used while registering either for both All India Counselling and State Counselling. You cannot switch Categories during Counselling. You can take part in the Counselling. But during the document verification, when you have to submit your Category certificate because your All India Rank is also due to your Category, if you fail to submit the relevant certificate or document, your admission will stand cancelled.