Should I do polytechnic in computer engg. and BCA? What is the eligibility criteria for ethical hacking? What is its scope in government?

Yes, it's a great option and also, I would suggest you to go for certification courses. Talking about government jobs, you can get a government job in their cyber security departments.

Ethical hacking is basically about learning how to find security vulnerabilities in IT systems. If you want to learn cyber security you can enroll for any of the training programs by http://pune.cssrl.in The training is possible in regular classroom or in online mode. A lot of career options are th