Ethical Hacking

For hacking, you must have knowledge to crack the pattern of the programme it is created on. For this, you must know the computers, so CS, will be the better option.

If you will do CEH course from Koenig Solutions, you will be certified within 5 days.
For more details, please check out the website :- https://goo.gl/ipHNz8

You must have a great knowledge of computer programming pattern. So, you may go after CS.

You can opt to become an ethical hacker after B.Sc CS if you have excellent computing skills. You may become a certified ethical hacker. A certified ethical hacker is a skilled professional who understands and knows how to look for weaknesses and vulnerabilities in target systems and uses the same knowledge and tools as a malicious hacker, but in a lawful and legitimate manner to assess the security posture of a target systems. The CEH credential certifies individuals in the specific network security discipline of ethical hacking from a vendor-neutral perspective. You may work to get CEH certification.

Dear,
Through B.Tech CSE, you would get the knowledge skills and understanding for the same and opportunities into ethical hacking and prevention.
All the best.

Your dream is to be an ethical hacker but my suggestion that you should first opt for any degree and then think of ethical hacking.