I am not able to correct even a single question in RC.What to do in CAT 2021?

Dont worry and dont be negative about your score and dont let yourself down. have patience and have courage to face the score no matter its bad, lastly start a new rc with open and happy mind

Have you determined your level yet? Cracku topic tests are adaptive so you get better when you practice more. Maybe at this point you do all the easy questions right, around 50% of the medium correct, and can't solve a damn hard question. Add an element of exam pressure too. So the key element is practice..!

Read as much u can and slowly everything will start falling in place