Hello, 

You can opt for any three of the options - B.Tech in Computer Science and Engineering, BCA or BSc in computer science in order to pursue your dream of being a ethical hacker. While pursuing any one of these you got to be focused on network security and breaches part, this way you can take your specialisation as ethical hacker in higher studies. Do some projects and publish papers based on security concerns. With all this, learn the basic nuances of ethical hacking programming paradigm.

All the best.