Hello,

Yes you can change it during the correction of the form. You should recheck  the application form if you have done any other mistakes or not. If you have done then you can change it during that time. If any mistake stays and it is found out during counselling then your application form will get rejected then and there itself. So make sure you have given every details correct and you ave documents to prove them.

For the guardian part its fine and parents are also our guardian and it won't be a  big issue for that. Even if you want to change it  you can do it.

Hope it helps!