Yes that's right. It can be used to express that you are going to update knowledge about a situation. for ex. if you were sick and not at work for two days. You could say "I will have to catch up".

Thank you..for wise explanation. And, it can be used for update the knowledge situations or not?

Hiya Venu It is a colloquial expression. If you have not seen someone for a while and speak or meet with them, you can find out what has happened to them or what they have been doing since you last spoke to them. You are 'catching up' with their life story. 'A bit of a catch-up' would be a conversation, in person or by phone, to bring yourself up to date with what has been happening in each others lives. Hope this helps Gavin