UPCAT

Use Shiksha's college predictor to know about college:
https://www.shiksha.com/b-tech/resources/upsee-college-predictor

No, as I can check, your son can't get this college.

There are 20%-30% seats are reserved for the students who are taking lateral entry in every college. The seats reserved for lateral entry may differ in some colleges. The fees for the degree engineering course may differ from college to college. So, you have to go through college and know yourself better. All the best. Lateral entry students seats are depending on the college that you have preferred for yourself as each college have its own quota for Polytechnic students. Fee structure is also depend upon the college that you prefer the most.

Very less chances but if you don't have any specific branch demand then you can get these college in 2nd counseling for sure.

https://www.shiksha.com/b-tech/resources/upsee-college-predictor
Please, go to the college predictor link I am sharing here to know about the college you can get. Here you can predict college according to your rank. Good luck.

Yes, you can get admission in IET at this rank. All the best.

I am listing top 10 colleges under this rank.
1-Galgotia's College of Engineering & Technology
2-Ajay Kumar Garg Engineering College
3-KIET Group of Institutions (Krishna Instt of engineering & Technology)
4-Chhatrapati Shahu Ji Maharaj University (government college)
5-Central Institute of Plastic Engineering & Technology (aided)
6-ABES Engineering College
7-M J P Ruhelkhand University {gov)
8-Bundelkhand University (gov)
9-Raj Kumar Goel Instt of Technology
10-BBD National Institute of Tech & Management.

No, there are only 85% chances that you'll get a government college.

You can choose any one if you want to take admission via reservation and if you have proper reservation documents, then you should go for BC.