Hello,

First of all congratulations to you and your son. Because he got very good marks in Feb attempt of JEE Mains 2021. Now his rank may be between 20k. Which is good.

In Andhra Pradesh 10% seats are available for general EWS quota. Your son get EWS rank also which is less than his general rank. In 97 percentile got NIT college in mechanical or electrical department. Infact information technology or food technology department. In this rank getting computer science engineering or civil engineering it's quite difficult. But may be get  in NIT Raipur or NIT Jamsedhpur or NIT Jammu. Infact you can get CSE in NIT Patna. I'll provide you a link below you can check it for which college you will get through this rank.

https://engineering.careers360.com/jee-main-college-predictor?icn=QnA&ici=qna_answer

All the best.