Colleges in Dehradun

Placements are decent in UPES. It's not very different from the placements from other colleges. However, a lot of people in the college do get in the core companies which is a good thing.
As far as the petroleum placements are concerned, the average placements packages are more or less similar to other branches, however there is a chances you can secure a very high package provided to intern at a core company like Schlumberger or Cairn India. A lot depends on your GPA if you are in Petroleum engineering in UPES.

Their is no coaching centre especially for UPESEAT in Chandigarh.

The fee is about Rs 38.000/- per semester.

Yes, DIT University is a recognised university, so yes you can go ahead.

I would suggest not to concentrate more on the cheaper colleges. I agree, these days, the cost of education is very high. You cannot get affordable and best colleges together. The cheaper colleges are not good in terms of faculty campus and placements. The expensive ones are much better.
You can go for DU and JMI colleges in Delhi. They have comparatively lesser fee structure as compared to the private one.