Yes, NIFT Patna can accept your son's admission even if he has a compartment in Mathematics from the CBSE board. However, he will need to provide the following:

• NIOS Exam Results: Once he completes and passes the NIOS exam for Mathematics, he will need to submit the results to NIFT Patna.
• Revised Marksheet: After submitting the NIOS results, NIFT Patna will issue a revised marksheet that includes the updated Mathematics score.

It's important to note that this process might take some time. Ensure that your son completes the NIOS exam as soon as possible and submits the results to NIFT Patna promptly.

You can also contact the NIFT Patna admissions office directly to confirm the exact procedures and deadlines for this situation.