As long as you are an Indian or Nepalese Citizen under 26 years and meet the prescribed medical standards, you can join NCC. If you are below 18 and 1/2 years, you can join Junior Division and if you are between 18.5 to 26 years, you can join the Senior Division. Please visit the official website https://indiancc.nic.in/how-to-join/ for more information.