Hi
CS IITR would definitely be the best option among these , although many ppl say that CS is loosing its demand but still computer engineers are paid the max . The average package for the cs department is the highest most of the time.
Then all the other three are almost at the same spot , without much of a difference.. Civil and mech both have got good  scopes ahead in future , rather Civil jobs wud be more booming in the nxt few decades , so Civil from delhi or mumbai cud be somewhat better than Mechanical.
Scope of civil engineering in India and abroad: Opportunities exist in the public and private sectors in large numbers in all branches of design, construction and maintenance, infrastructure development in both India and abroad. Right now constructions industry is booming as there is growth in infrastructure requirement throughout the country. This is going to stay for next few decades. Scope of civil engineers lies with many developing countries in middle east, Africa, Asia where infrastructure development is picking up and Indian engineers are in great demand.