Hi Priyanka. I can recommend you a very good website to improve your English listening skills - elllo.org. You can find both monologues and dialogues with people from different countries, and I suggest you first always listen to the audios/watch videos without reading the script or subtitles, otherwise you won’t be training your listening comprehension, as you will focus on reading.
You’ve mentioned in the comments that you work in a multinational company and need to communicate with people from different countries. So possessing strong communicative skills is a must in your job. If somebody’s speaking very fast you can and you should ask them to speak more slowly, repeat what they’ve just said or you can also summarize their points and ask them to confirm. Remember that communication is a two way street so it’s not only you who is responsible for the outcome of a meeting/conversation. Effective communicators make an effort to be understood, they make sure their message is clear no matter who they’re communicating with, a native or a non-native. I think you might be interested in reading a book called ‘Effective international business communication’, there are a lot of useful tips on how to communicate effectively in a context like yours.
Hope that helps.