Hello Aniket,

If your marks are below 75% and you want to switch to NIOS (National Institute of Open Schooling) to take the exams in 2025, here are the key points to consider:

1. Eligibility : You can appear for JOSAA (IIT/NIT) entrance exams after completing 12th through NIOS as it's a recognized board.
2. Subjects : You need to take exams for 5 subjects, which must align with your eligibility and course choice.
3. JEE Main : You can be eligible for JEE Main by passing the 12th exam through NIOS.
4. Minimum Marks : You must achieve the required score in JEE Main for ranking and admission.

Hope it helps !