Hello Aspirant,

See if you are seeking to complete your 10+2 from NIOS then you don't have to appear for class 11th examination you can directly appear for class 12th examination from NIOS and if you have already completed 12th with PCB and seeking additional Mathematics certificate from NIOS then also there is no need to appear for class 11th Mathematics examination because you can directly appear for On-demand examination of Mathematics from NIOS for class 12th.

I hope this information helps you.

Good Luck!!