ITR of Educational Society

Educational Society
A School
PAN : AACADxxxxR

From this it can be seen that its an AOP

When i Login i found that previous 2 year Returns was ITR 7 and that had become defective and even then Processed

Please tell me how can i know y return got defective in previous 2 years I wanna know which return will b filled

ITR 7
Or
ITR 5 ( Software is suggesting this)

And if its defective why Department processed it