Am I eligible for ethical hacking after graduating? I am pursuing BA LLB and I have interest in computer and programming.

Associate Diploma in Cyber Security from CSSRL may be most suitable for you. You can check details from website or by discussing with their admission counsellor.

I think BCA is better than other courses, but also ethical hacking has better scope and placement in new company, so focus on hacking.

I think BCA is best for you. You can go for Bachelor of computer application or MCA for programming.