Hi Harsh,
Before everything I just wanted to know whether you have taken and answered the various engineering exams like JEE, BITSAT, Manipal IT etc. If you have answered any of these exams and have passed and you can get into any of the good colleges like IIT or NIT or Manipal or BITS then do choose B.Tech as an option. Keep that your first preference. Secondary, when you do not get into any good private/govt colleges for B.Tech opt for B.E. But remember since you want to become a software engineer your best subject should be I.T or C.S If nothing else works out then try for B.Sc in CS or I.T it's because in India B.Tech and B.E have a lot more scope and you get instant jobs on these courses. Whereas if you take B.Sc you will have to do m.sc in order to get a good job with a good salary.

Good luck