Hello Aspirant!

Science Olympiad Foundation (SOF)  is an educational foundation and a nonprofit organization, established in 1999, based in New Delhi. Science Olympiad Foundation is popularizing academic competition and assisting development of competitive spirit among school children.

If you miss the any exam like NSO, ISO, RMO by SOF then nothing can be done.
Because if you miss then you cannot be able to give the exam again. These are conducted once on a particular date and reexaminations were not possible. If you have registered online or given your email during your registration process for SOF exams, then they can send you updates as well as your Identity card through your registered email.

For more details you can check Careers360:

https://school.careers360.com/articles/sof-results

All The Best!