How can one come to conclusion regarding topic for PHD I am trying to get my topic from few days yet I am in unable to narrow down it
So I would like to know how budding research scholar narrow down it

PS : Don't include as Google I tried all of it but most of papers are not for Free access like IEEE one so it's more difficult
Unfortunately, narrowing your research plan actually requires, well, research. This is why commenters have noted that it might take a year to come up with a problem suitable for the dissertation. Not knowing your specific academic culture (country, university, ...) it is hard to give precise advice here. However, it is possible that you are thinking that you must do more, now, than is actually being asked of you. 

I think that it is pretty rare for a beginning PhD candidate to actually have a worked out plan. It certainly happens in some cases where a person has worked in an industrial lab and has already found an interesting but unanswered question. It might also be true of some exceptional graduate of an exceptional Master's program. Most, I think, new doctoral students, however, come as seekers, initially. 

Let me suggest two things. First, talk to other students who have been in this situation in your new program to see what they did and what was actually expected of them. What sorts of questions were asked in the interview? This will give you more realistic expectations of the requirements. 

Second, assuming that you are not actually expected to have a fully formed research plan already in hand, be prepared to discuss both what you know in the field and what specific things interest you the most. Why do you want to study Machine Learning? What makes it interesting to you? What has clearly been solved and what (in general) still needs to be done? What sorts of real world problems would be solved if advances were made in a particular direction? ...

That may be all that is asked for at this stage. Perhaps the faculty is interested to know your deep interests so that they can help you find the correct advisor. It may be no more than that.

But ask other students first so that you are more sure about it. If it is as I describe you can be more comfortable. I can't guarantee that they don't want more, of course, but I think that would be unusual and expected only at an exceptional institution. 

I often tell students that "You aren't here to prove that you don't need to be here."