Hi,
First, don't be panic during the interview session. Relax and be prepared before going for an interview session. "Tell me about your weakness" means in what area do you need improvement? It does not mean how bad you are in your work. You may have some areas or skills or knowledge to improve and you are enrolling for training, reading, or joining classes to improve yourself. then you may mention the efforts that you put in to improve yourself and do better in any given opportunities.
6
Its ok to tell your weakness. Do not avoid to answer & try to convince the interviewer that you do not have any weakness at all. If you trying to avoid such question, the interviewer might be focusing on your weakness & end you will lost the opportunity.