hello surya,

i think you're little bit confused with your b.tech admission and college,please be sure of decision.

okay, the placement in allahabad is also good.truely this answer is upto you, because you should work hard whatever the college is.the admissions for b.tech in iit allahabad is only through JEE MAIN entrance exam.for admission details, plz refer the official website of iit allahabad.

https://www.iiita.ac.in/academics/admissions_process/

all the best...:D