Dear Vishal,

One may get confused between these three but they have their suble differences between each other. Btech in CS will put you in coding and technical aspect, BCA and MCA will also get you in the aspect of using software and computer related. BCA costs less than B tech. For BSc CS, it is more of a general degree and you can pursue MCA after both Bsc cs and BCA. You will get the engineering tag after pursuing BCA+MCA.

At the end it boils down to what you like, whether you are a coder or not, are you just interested in computer aspect or more than that?