Dear aspirant !

Hope you are doing great.As you passed your 12th in science and now you want to go for PO exam .You have now a lot of time in which you can do whatever you want to do .Also you scored good without any preparation as you said.So in my opinion if you will Focus and consistent then you can crack any exam no matters whether it is bank exam,CGL,chal, UPSC etc.Everything depend on you .With the graduation ,start your preparation for the exam.

Best wishes from my side!

Thanking you!