Hi Aspirant,

Since you have already done 12th with PCB and I assume you have already passed these three subjects successfully. And now from the combination of PCMB you only have Mathematics missing as per your essentials. So Yes, you only need to give Mathematics from National Institute of Open Schooling(NIOS).

You can refer the official website for more informations,

https://nios.ac.in/

Hope you find it useful.

Good luck!!!