Hello Sahib

No, you cannot do 10th or 12th from two boards at the same time as it is not allowed by any education board in India.

If you are registered with a certain board, you can change it to any other (mostly in 9th and 11th class) but you cannot get registered with two boards at the same time.

If something like this is found out, both results will be deemed cancelled so it is advisable from my side to stick with only one board whether it be CBSE, ICSE or any state board etc and give your best.

Thank You!!!