Bro , I am sorry to say this but there are three coloumns in questionarie when renewing study permit .
a) have you ever been arrested
b) have you ever faced criminal charges
c) convicted of criminal charge ( don't knw exactly )
Unfortunately , you have to say yes to all the three coloumns . Don't act anything foolish here by saying NO as it can give or immediate refusal and a ban from Canada .
Now , what you can do explain it in the space below these questions that you have been charged with 3 or 4 charges but gort withdrwan from some of them ( as u said ) and got a conditional discharge in one of the charge ( as u said you are facing crimnal chrge fr 2 years ) .
And must attach a SOP stating how that affected your studies , you want to study and forget about what happened . You don't want this mistake to ruin your career but focus more on your course of study here .
You can also mention if you made any donations and whatever you did to overcome the mistake in the space below those three questions or sop ( if you got a conditinal discharge your lawyer must have shown some these kind of things like guilty plee lettr from you or donations ) . If you don;'t know about this contact him .
Hope that helps