Never get into this discussion until and unless you are in the last phase of the interview process. If they question you in the first level of the interview process, then just say, "Why don't we discuss this in the last round of the interview?"
If the same question is raised in the last phase of the interview, you can decide the expected CTC based on the company standards (Small, Mid-level, ISO certified, MNC, etc.). Before attending the interview, check portals to find out what this company is paying its employees. Also, research what is typically offered to a candidate like you with your experience and expertise in the market. With this information, I hope you can set your expectations.
It would be great if you could persuade the interviewer to reveal the package they have in mind for this position. If that's acceptable to you, proceed; otherwise, suggest a range like a 20% - 30% hike. Now it's up to your skills to negotiate this.
Good luck to you.
Regards,
Babu