Which is the best course among B.Tech and BCA?

I would suggest B.Tech as after B.Tech you get a lot better opportunities than BCA. The placements for B.Tech students are excellent as every company offers quite an average salary but for BCA students the package is very less and the location for that job may not be in your home place. 

The right course to pursue between B.Tech and BCA will depend on your choices, career ambitions and abilities: 

BCA

This programme is well suited for people who wish to pursue any career that involves software programs, designing web pages, or even managing databases. Computer Study Skills are BCA's