Hello aspirant!

First of all I would like to tell you that BTech. is a four-year undergraduate program whereas BCA is a three-year undergraduate program

For BCA you need to have good grades in your respective streams like arts/science/commerce whereas for Btech you need to clear the entrance exams

See BCA makes you adept at the application level of computers whereas BTech makes you proficient at the 'technical' level

A BCA graduate is a software programmer armed with the knowledge of scripting as well as programming languages like C, C++, Java, HTML, PHP etc. whereas BTech graduate has detailed knowledge of both hardware and software.

Hope that it would be helpful!