Hello aspirant,
You can always re try.
Or you can choose NIOS Board.
To beeligibleto be admitted to Class XII, candidates need to have passed the secondary exam, i.e., standard X examination. Candidates need to be 15 years old.
NIOShas started Open Basic Education courses in keeping up with the spirit of Education for All.
All the best.

Hello dear
You can give the reappearing exam for that subject.
Good luck

Go for NIOS BOARD and save your precious year.