Can any school give admission to new student in 11th before boards result ?

i am the student of mahavir senior model school delhi .i had got 69 marks in maths and 63% in pre board exams.But my principle SL JAIN is not giving me commerce with maths . Insted of me he has given admission to a girl of st.thomas school .Iam saying to him that i will get 85 marks in maths. But he is not giving gurantee that after boards result he will give me commerce with maths.He is denying my choice.so tell me what shall i ido our school has started cles