Is CCNA better after completing B.Sc?

Yes, it is better one as it will enhance your knowledge towards networking and further more now a days networking CCNA are in most demands. Also after CCNA you can go for advanced level certifications and also top IT companies looks after this high level certifications.

Yes you can. CCNA will further add a new skill to your skillset. Furthermore networking is in demand these days. CCNA is a good choice.

CCNA can be done after B.Sc. This will already give you a basic idea on computer Science if your B.Sc is from computer science.