Hello Sajal, 

This is the problem of many students whoever chooses to do b.tech. Many of them think that they are same but they are not. CS and IT are like twins simillar in many case but are not same. 

Fundamentally, (as it is said) CS is hardware oriented. IT is software oriented. A CS engineer can both be a hardware and software engineer. An IT engineer won't be preferred over a CS engineer for hardware oriented jobs.

Syllabus

CS students are exposed to theoretical Computer Science that includes subjects like Theory of Computation, Algorithms etc. Usually, these 2 subjects aren't taught to IT people. Compiler design is the subject that is taught to IT and not CS. Only 3-4 such subjects.

Placements

The placements are similar. There are very minimal chances of seeing a company that allows CS students but not IT students to sit for the placements. No differentiation on the basis of stream. Be it a CS student or an IT student, both have equal and fair chances in placements.

Preference:

Normally, students tend to prefer CS because everyone prefers CS :p (We believe in following the herd). Even, I preferred CS because my cousins told me to without knowing much about it. However, it is just a myth. As long as you are good at your work, these myths won't affect your future.

Masters:

Even the GATE exam is conducted together for CS and IT students in the name of Computer Science and Engineering Technology. And, anyone can change their stream from IT to CS or CS to IT through GATE at Masters level. But, most of the IITs do not have a separate stream for CS and IT but only one stream at Masters level. This year, IIT Khgp merged the two branches - IT and CS into one.

Conclusion :

CS and IT are like unidentical twins from the same father. Both get the same amount of pocket money (opportunities and chances of placements). They are the fruits of the same tree but are perceived differently by others. Only their names and some interests (subjects) are different.

Hope you have understood the difference between Cs and IT.

Thank you