What is the difference between BE & BTech???

There is no major difference between these two degrees in terms of value and future job prospects. Let's go back to the history of Indian education system. After independence there were universities which provide different degrees in arts,science, commerce and engineering as well and some of the universities which provide dedicated engineering degrees.
Universities which provide other degrees along with engineering called their engineering degrees B.E (bachelor of engineering) and those universities having dedicated engineering degrees only called their engineering degrees B.tech (bachelor of technology).
IITS offer B.Tech degrees because they were among the first institutes established exclusively for engineering education.
No degree, B.E or B.Tech is superior to other. Both of them having similar scope and future.