Sir can a student change his stream from science to commers, my brother pass his X1 in science and not able to do x11 can he change

He will have to repeat his xii. Best is that if he takes admission in a diploma of his interest and then be admitted in a bachelors degree in the second year , saving one precious year. Check such schemes from some good college sites like JNTU, LPU, GALGOTIA etc