What is the base salary if we complete CS from NIT Rourkela and get approximately 7 CGPA? What is the average package I can get?

I don't think many companies even consider CGPA as the criteria for evaluating your eligibility to get placed. CSE students especially have to work on their coding and problem-solving skills more than their CGPA. I am not saying CGPA does not matter at all, what I mean is it's not the main criteria. You still need a good CGPA to qualify for the cutoffs set by companies. Most companies are okay with a decent 7 while some even let you sit with a CGPA around 6. Only a few government companies like CDOT and DRDO, set high cutoffs. The number of companies expecting a high CGPA is usually very low.

One of my friends at NIT Rourkela stated that there is no direct connection between your CGPA and the package you receive, rather it all depends on individual skills. If you are a CS student, bear in mind that your interviewer will expect good coding skills in any of the high-level programming languages like C/C++/Java, etc., a strong grasp of data structures and algorithms, basics of operating systems, and some fundamental theoretical concepts of database and networking. Such skills will overcome even your low CGPA. 

NIT Rourkela CSE average package 2023 stood at INR 21.87 LPA . So it can be said that as a NIT Rourkela student, if you have a CGPA of 7+ you will be eligible to sit for placements of most CS companies but your chances of selection depend on the skills you developed through the period of 4 years.