BCA

Ankit, Although BCA and B Tech are graduate programs, both are entirely different streams of study. Bachelor of Computer Application is concerned with software designing, data base management and operational functions with the help of multifaceted data within a computer.
B Tech is a professional degree course, which deals with the study of engineering principles in diverse streams, which are the base for the developments in Science and Technology.
Key differences between BCA and B TechBCA is Bachelor of Computer Applications whereas B Tech is Bachelor of Technology.BCA is solely computer related whereas B Tech incorporates technical subjects along with computer applications.The former is a degree course whereas the latter is an engineering discipline.BCA Professionals can seek for career in IT industries or software companies only whereas Engineers can opt either for technical jobs or for software jobs.
Comparing BCA and B Tech, the latter is a much better course, which has reasonably good employment opportunities.
Now the most important thing is the university/ college that you choose for your degree. These days we have many good government as well as private universities like IITs, IITTs, NITs, LPU, SRM, etc offering admissions in different engineering branches. Some of them offer admission just on the basis of tests like JEE and some offer you direct admission too on the basis of your marks in previous qualifying exam or test conducted by them only. So, you can check the websites of these universities to know the course and fee details.
Best of luck to you.