One of my friends joined Civil Engineering in the 2nd year but he dropped out of it. Economics begins making sense when you start taking up electives of your choice. However, if you have gotten any engineering branch, then do not drop out. The current job scenario in the Indian market is pathetic and you must make it big.
In your final year, CDC's M.Sc will be beneficial. You can also pick your electives as my friend did in finance and entrepreneurship and soon got an internship at an investment bank. He didn't stop there and further explored Eco-Fin by doing a thesis.
The perks of not dropping out are as follows:
BITS will give you immense flexibility to develop yourself. You're not bound by your choices because you can make many other, any other. Your peers will be a group of intellectuals who want to do something in life and they'll support you throughout this time.