Central Board Of Secondary Education [CBSE] — Not satisfied with school marks

I am saksham singh mehra, of class 10th section- B. I was studying in army public school asc center bangalore. And because of boards cancellation i am shocked, as i was preparing so hard for boards and now the result the school gave me, i am sure was pretty much based on preboards, so i am really unsatisfied with it as i was attending online classes from dharchula uttrakhand and trust me there were no signals of any kind of network, and we moved to dharchula from bangalore, because my father was posted there and he fell sick suddenly, so we had to rush from bangalore to dharchula. So i was in dharchula from August 2020 to jan 2021 and was unable to study at all. So beacuse of that i scored very less in preboards. Please tell me if i can write a exam as you said in the guidelines that 'any student not satisfied with the marka alloted to them by their schools can sit for an exam'. Please Contact me on [protected]. You can text me and also email me on [protected]@gmail.com. please help me.