India

NIT Surathkal is very difficult. However you can tryout the following Engineering colleges of your state.
1. HKBK College of Engineering, Bangalore
2. MVJ College of Engineering, Bangalore
3. CMR Institute of Technology, Bangalore
4. KLE Technological University, Hubballi
5. Ballari Institute of Technology and Management, Bellary
6. PES University Bangalore.

Your son KCET rank is really decent. Based on the KCET rank, your son can get the following engineering colleges in asked category under Karnataka domicile.
1. PES University (PESU)-CSE& ECE
2. RVCE Bangalore-Mechanical
3. Dayananda Sagar College Of Engineering -Aeronautical& Telecommunication
4. BMS College of Engineering-IEE& Mechanical
5. Reva University-CSE&ECE
6. BIT-EIE
7. University Visvesvaraya College of Engineering-Mechanical.

You can expect a rank under 5000 easily. You will be treated as a general candidate itself because you are a non Karnataka student.