Yes, your son can definitely pursue higher studies abroad even if he clears his chemistry compartment exam through NIOS.

Many universities and colleges abroad accept equivalent qualifications. NIOS is a recognized board in India, and its certificates hold equal validity as CBSE certificates.

Once your son clears the chemistry compartment exam through NIOS, he will have two mark sheets - one from CBSE for the passed subjects and another from NIOS for the compartmentalized subject. Both these mark sheets will be considered valid for admission to foreign universities.

However, admission requirements vary from one country and university to another. It's essential to check the specific requirements of the desired university or country. Some might have additional language proficiency tests like IELTS or TOEFL as prerequisites.

Therefore, it's advisable to start researching the admission process for your desired universities well in advance to ensure a smooth transition.

hope this helps you!!