If you have retained your Category as EWS as the Category in the NEET PG application form but selected General Category as the Category during Counselling, it will not be changed. The correction window is your only chance at making corrections to your NEET PG application form and unfortunately thereafter you cannot make any changes to your Category or whatsoever details. At this point in time, you only can hope that your EWS certificate comes in atleast by the 26th March because once the seats have been allotted, reporting to College begins from March 26th and continues until April 3rd. Or you may have to wait until Round 2 to get your EWS certificate. At this point in time, this is one option that you have. Because if you fail to submit relevant Category certificates, your admission will stand cancelled.