Hello. It is difficult to tell exactly now which college he may get since your percentile and rank may differ because it depends on the tot. no. of students appearing in the April exam. NTA will release the Overall merit list based on the no. of students appeared and best of two attempts of the students appearing twice. So to know your son's exact rank and a particular college cutoff you need to wait until the April exam ends.

According to his precentile the probable rank will be 186,873 - 206,873. (Assuming him in general category). Based on this he may not be eligible for JEE ADVANCED. 

I would recommend for your son to study hard and prepare well for the jee mains April session and try to score a percentile of 90+.

For study materials or how to prepare for jee mains april you can check the below link.

Https://www.entrance360.com/knockout-jee-main-april/

Hope this helps. For any query you can comment down below.

Good luck!