Is BITS Pilani worth a year drop?

Yes, BITS Pilani is worth taking a year drop irrespective of whichever branch you will be getting. 

I will tell you an anecdote about a friend who wanted to get admission at BITS Pilani but failed to clear it in the first year. He ended up taking ECE in an average college but still yearned for BITS Pilani and decided to give himself a second chance. Surprisingly enough he got MSc. Economics in BITS Pilani. He decided to take the dual degree and convinced his parents who were against the idea of dropping ECE and taking Economics at a remotely located college. 

Fortunately, luck stayed on his side and he was offered a stipend in his internship much higher than what his counterparts were earning in their full-time jobs. Later, he got admitted to the Masters of Finance program at Massachusetts Institute of Technology. The year drop did not stop him from achieving great heights and fulfilling his dreams.

Ultimately, more than academics and faculty, it is the environment you are taught under and the people you interact with that affect your college life greatly. BITS has the best crowd because of the no-reservation policy and the opportunities and exposure offered are excellent.