Hello Srikanth, when non-orthogonality between regressors and errors is suspected in an analysis, the endogeneity test is conducted. You don't have to use the J-statistic for endogeneity test especially in instrumental variables regression, if you are not very conversant with it. The Durbin–Wu–Hausman test can also be of help. You will find the details in the attached documents for both questions. You could use JMP STATA software or any other of your choice.