Hii aspirant ,

Coming to your question, first I want to congratulate you as you have cleared the NDA written exam, now  as you have mentioned in your question that you have passed the class 11 and 12 but your marksheet is in the college I will suggest you to take the original marksheet from your college because when you will be going for the interview they will ask for the original one at that time .

Hope this helps you , fell free to ask if you still had any doubt,

Good luck.