Hi aspirant,

Since your son has taken basic maths for the session 2021-22 and has even road determine examination it is not possible to change it to standard mathematics till term 2. However there is a provision made for these kind of students who have initially chosen basic mathematics and want to make career with pcm as subjects. They can appear for the compartment examination for standard mathematics that will be conducted after the end of term 2 and therefore be eligible to choose mathematics as their subject in higher secondary education.

Hope it helps!!