Hello, dear

Both are the best branch.& it depends on your interest /choice of what you want to become & what's your passion.

*If you want to become a hacker, data scientist, coder, software developer then IT will be the best choice for you

*If you are interested in designing the mechanical parts of vehicles then mechanical engineering is the best.

*But choosing the IT branch has better benefits & more scope as compared to Mech. because nowadays CS & IT engineers are in demand because India has to become Digital India as per the future project of our PM. Mechanical fieldwork is required but not in the case of IT.