Yeah! If you are open school student then also you are eligible for the JEE MAINS and ADVANCED provided you must secure a marks equal or greater than 75% in your 10+2. If you get a chance to get admitted in NIT, IIT or any other government college then you will not face any problem. But there are some private colleges, which don't consider the student of open school to provide admission but this kind of colleges are very few.

To know more about JEE MAINS visit the link below:

https://engineering.careers360.com/exams/jee-main

To know more about JEE ADVANCED visit the link below:

https://engineering.careers360.com/exams/jee-advanced

I hope this answer helps. All the very best for your future endeavors!