From view of career scope and prospects I would suggest you to prefer Electrical Engineering at Delhi Technological University over IIT BHU Pharmaceutical and IIT Patna Metallurgy. DTU has excellent infrastructure, faculty and research facilities and is one of the Best when it comes to Electrical Engineering in North India, next to IIT Delhi and IIT Roorkee. The institute has a very strong employer outlook and most of the Top Companies like Tata Motors, Texas Instruments, Adobe, Microsoft, Google, Intel are regular recruiters from Department of Electrical Engineering.

However, this is my perception, incase you are seriously interested in pursuing Engineering from One of the IITs  I would suggest you to prefer IIT BHU over IIT Patna, as you will have a better exposure and more opportunities. Secondly, Metallurgy is a good branch if taken in one of the Older IITs, whereas the MT Department at IIT Patna is just a couple of years old and lacks in experience, projects and expertise in faculty and research. At IIT BHU, you  will have a number of Non Core Opportunities in IT, Software, Finance and Analytics domains besides getting a fair chances to securw a Branch Change in first year, perhaps the grading system at IIT BHU is one of the Most relaxed among most IITs.