B.Tech

I think the cut-off rank for DTU will go high.
As JEE 2017 was tougher than JEE 2016.
You can see it as the cut-off score in 2016 was 100 and in 2017, it is 81.
So, tough question paper lowers the cut-off.
So, it means there are chances of adding 1000-2000 in cut-off closing rank.

Kindly use this WBJEE college predictor tool to know more insights about the available colleges.
https://www.shiksha.com/b-tech/resources/wbjee-college-predictor

Tuition fee waivers are some of the students selected according to their performance in 12th. Their fees is much less as compared to the regular students.

You have to fill the forms of the various exams. Colleges for lateral entry. You can also change branch in B.Tech for lateral entry. Almost all the colleges offer lateral entry. So, you don't have to worry about the college.

No, Ujjain engineering college is not that good for doing BE in chemical engineering. If you want to do Chemical engineering, do it from some other college, the placement here is also not good.

Chandigarh University has good placement record with the highest package received - 24 LPA. Average salary package is 3- 4 LPA for 2016 for BE CSE course.
But all these depend on your skills only. So if you are talented you can bag even more good packages.

You can go for any one of the above. It's totally upto your choice. Since, you have done your diploma from mechatronics so it would be better if you pursue your from same.

Hello Adnan,
Please refer to this link to get more insights of the colleges and branhes:
https://www.shiksha.com/b-tech/resources/mhcet-college-predictor.
However, as per your rank, you will get top colleges under MHCET domain.