What is avg packages a student get inIIT KGP mining

For Mining Engineering prefer ISM Dhanbad, but if you are not getting and you are interested then go for IITKGP, its placement is also good
There are many companies in Mining field visiting IIT's, some are
Vedanta Resource, NMDC, NALCO, Hindustan Zinc limited, HINDALCO, COAL INDIA, Gujarat Mineral Development Corporation, Neyveli Lignite, Tata Steel, Rio Tinto, Shell, Cairn India, Reliance power, etc