Hello Shivangi,
If you want to prepare well for NID DAT general knowledge and current affairs section, start reading newspapers. Read at least two dailies (Newspapers). It won’t only help you in your examination, but it will also help you in the long run (You will be better informed and this will give you a lot of confidence as well. If you are looking for books that will help you with general knowledge and current affairs here are some of them –
Manorama
Arihant’s Current Affairs
General Knowledge book by Lucent
I hope this was helpful