See for being an IAS officer there is no need of being an engineer or from any professional field. The only requirement is that you have to qualify all the tiers of UPSC CSE with good marks and you must have a graduation. Now as you are interested in Engineering then its always better to choose the best.

Among the two you have provided I would recommend you to go for VIT CHENNAI.

VIT have a very well organized curriculum such that the curriculum provides adequate skills to work in industry as well as to pursue academia. Also the faculties are very well experienced and are active in research. VIT offers a very good rate of placement about 91%. Thus if you want to get admitted in an engineering course then I would say its better to go for VIT CHENNAI. VIT CHENNAI have very good infrastructure which is really  good fact for science students.

** I would highly recommend you to conduct a research by yourself. If you find my facts relevant then only go for it , else take the decision  which will be the best for you.

To know more about VIT CHENNAI visit the link below:

https://www.careers360.com/colleges/vellore-institute-of-technology-chennai-campus

To know more about JNTU visit the link below:

https://www.careers360.com/colleges/jntuh-college-of-engineering-hyderabad

To know more about UPSC visit the link below:

https://competition.careers360.com/exams/upsc-civil-services-exam

I hope this answer helps. All the very best for your future endeavors!