Hi sir,
You have neither mentioned your category here nor your home state.
So, assuming you are from General Category. Here are the probable colleges that your son would get CSE/ EE/ ECE in:-
CSE:-
1) NIT Andhra Pradesh
2) NIT Uttarakhand
3) NIT Agartala
4) Newer IIITs like Kota, Sonepat, Trichy, Kancheepuram, Sri city
5) NIT Meghalaya

ECE:-
1) BIT Mesra
2) IIEST Shibpur
3) NIT Goa
4) NIT Hamirpur
5) NIT Raipur
6) IIIT Kancheepuram

EEE:-
1) BIT Mesra
2) NIT Goa
3) NIT Andhra Pradesh
4) NIT Uttarakhand
5) NIT Jamshedpur

You can use our college predictor to check your chances to get into different NITs, IIITs and GFTIs:-
https://engineering.careers360.com/jee-main-college-predictor

H ope it would help.
Thank You.