Hi Nanda,

All the main 5 subjects are considered in admission to NIT or IIT. These subjects are as follows:

• PHYSICS
  
• CHEMISTRY
• MATHEMATICS
• LANGUAGE
• ADDITIONAL SUBJECT(IP, IT, CS, BIOLOGY, ETC.)

For admission in IITs, students must be in top 20 percentile of their respective boards.

https://engineering.careers360.com/exams/jee-main
https://engineering.careers360.com/articles/jee-main-eligibility-criteria

Hope this helps.

Thank You.