VIT Vellore

Predict engineering colleges you can get on the basis of your JEE rank: https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor?utm_source=cconnect&utm_medium=CR_JEECP&utm_campaign=8321427. In VIT placement are decent for civil but one should not depend on placements from VIT.
Most of the students go for a higher education. The highest pay till now in civil is 9 LPA which is rare.
Average pay around 4-5 LPA. Top companies visited are such l&T, Godrej and Tata housing. Mostly your role is such as site engineer and junior site engineer are offered. You have to have a minimum of 8.4 CGPA in order to even think about a job.

It is better to choose chemical engineering from reputed NIT. Chemical Engineers have lots of job options in manufacturing industries like specialty chemicals, foods, plastic, power production, tyre manufacturing, nanotechnology, mining process, synthetic fibers, chemical engineering designs, nuclear energy, materials Science, biotechnology and petrochemical plants. Students, who dream to be in research field, can fulfill their desire through this career, as there are some graduates who prefer to work in laboratories. A decent number of students also turn into a chemical engineering professor in top institutes or universities.

CSE is good branch. VIT also a good college but if you get seat in top nits as NIT Warangal, etc. Then, you should go for NIT or it depends on your interest also you want to choose CSE or chemical engineering.
Good luck.

Try your luck in JEE Advance because with that rank you are not getting anything in JEE Mains counselling. And in private go for BITS or Lovely depending upon your calibre.

Average salary
$80,115 per year in the United States
INR 243,041 per year in India. Production engineering is not having that much of scope when compared to other departments. But this won't be a matter when u r passionate about your aim. Good luck!

If your rank is 18000, you will get NIT and IIIT. I can't say about CSE but you will get other branches. Preferring VIT over NIT IIIT is what I feel is not good. You can even get CSE in other private colleges having more exposure to coding. Good luck.
Hope it helps.

No option to change branch.