Hello Janaki,

To get seat in engineering colleges in coimbatore , your son has to either give the all India based engineering exam i.e. JEE Main. Also, there are other state level entrances which he can give to get admission into the respective colleges of his choice. After qualifying the exam, he has to attend the respective counselling processes of the colleges to take admission. Below I have provided the list of colleges in Coimbatore where he can apply - 

• Amrita School of Engineering
• Coimbatore Institute of Technology
• Government College of Technology
• Karunya Institute of Technology and Sciences
• PSG College of Technology
• Sri Krishna College of Engineering and Technology
• Hindusthan College of Engineering and Technology

You can also go through this link and checkout the list of top engineering colleges in Coimbatore : https://engineering.careers360.com/colleges/ranking/top-engineering-colleges-in-coimbatore

Also, you can visit this link and see the list of government colleges in Coimbatore : https://engineering.careers360.com/colleges/list-of-government-engineering-colleges-in-coimbatore

Good Luck !!!!!