Hello,
.
Yes, obviously your grades matter. Let us talk what happens, You will be only allowed to show your interest/skills once you are hired by  other educational institution or any company. So, even though your grades are not only the thing matters but play a crucial role in next step. In your next step of education, you will be selected based on your previous educational grades. So, need to give your best in every step of your life

Hi aspirant...
Marks doesn't matter the thing which matters is your skill give your best in that field where you want to make your career and nobody sees marksheet everybody sees the ability. Go for it . Good luck don't loose hope you can get better results if you work hard.