I have been trying to search few users’ old tweets, old tweets as 6K back but after trying all websites, I can just track 3200 tweets not more. Anyone who can help me how to find them?
Twitter limits the amount of tweets that can be served through the API. From the Twitter API docs:
(...) The timeline returned is the equivalent of the one seen when you view a user's profile on twitter.com.
This method can only return up to 3,200 of a user's most recent statuses. Native retweets of other statuses by the user is included in this total (...)
Tweets that are older still exist, but can only be fetched by a specific ID
So, to answer your question: I'm afraid it is not possible to fetch 6k tweets from one user. At least not with the Twitter API that's available to the public.