Usually, the IT and CS branch students of IIEST Shibpur get the highest salary packages. Many industry giants such as Google, Directi, Amazon, etc. take part in IIEST Shibpur placements. In a recent placement drive, an IT student received a salary package of INR 42 LPA from Microsoft.
Having good programming skills and good knowledge of algorithms, system architecture, etc. can get you these CS jobs. The roles and packages offered vary depending on the skillset and knowledge of the students.
You will definitely be able to fetch a really good package by pursuing one of the many streams and courses offered at IIEST Shibpur.
Generally, the starting salary package of a Mechanical/EE/Civil/Met is lower than that of CS/IT graduates. Once you enter the industry, your pay will depend on the quality of work you deliver.
So, you should get into the branch of your interest and develop yourself in that field. The results will definitely be fruitful.