It’s better to denounce the sheep mentality and think from your own perspective. If you are attracted to CS because of its lucrative branches, I suggest you not go for new IITs as the placement scenario is not that good.
IIT Roorkee, on the other hand, is a very old Engineering college with an excellent legacy. The rich coding culture motivates even non-CS students to learn coding to apply for software companies. The new IITs soaring in Guwahati and Indore lack the necessary resources and dynamism of coding.
One can always work on their noncore branches and gain additional skills to compensate for their flaws. But one should risk the Institute and always go for the best.
It’s better to choose IIT Roorkee Mechanical than CS in new IITs.