BITS India offers direct admission to NRI students through the International Student Admissions (ISA) program rather than the DASA quota, which is primarily for NRI admissions to other engineering colleges in India. For a more personalized and comprehensive guidance, you may consider consulting Invicta Career Consultancy, as they specialize in assisting students with admissions processes and can provide detailed information and support tailored to your son's specific situation, While there are other options available, hence you can pay a visit to their website (icclearning.com) and get consult with them for better guidance. All the best to you.