Dear Aspirant ,

You need not to worry if you don't have certificate , offices are now being open so you can visit them for making your category certificate . Certificate is only needed at the time of counseling not otherwise so before counseling you need not to worry about certificate . Even at the time of JEE Advance form filling you can fill as General EWS as your category .  During JEE Advance form filling you can give a declaration in lieu in place of your category certificate in which you declare that you don't have certificate now but you will present it at reporting centre . So my suggestion will be go and make a certificate , it will need some time till but I don't think it takes more than a month and you have approx three months before counseling begin . So fill a declaration in lieu in Advance form and try to get a new General EWS Certificate . Or you can choose your category as General during JEE Advance form filling . But the best option give declaration in lieu and try to get a new form before August . One more thing I am giving you link of jossa business rule of privious year so go to page no 42 and read point number 65 . It is mentioned there that if you unable to present certificate how your category be changed .

https://www.google.com/url?sa=t&source=web&rct=j&url=https://josaa.nic.in/webinfocms/Handler/FileHandler.ashx%3Fi%3DFile%26ii%3D155%26iii%3DY&ved=2ahUKEwiysLCvzM_pAhVDWysKHc89Ax0QFjAJegQICBAB&usg=AOvVaw2xDRZWoE1Yn0P4lm6QSHZP&cshid=1590429743365

And one more thing never ever try to provide fake certificate it will lead to your disqualification ok .

Good Luck .