I have been working on a review paper. After publication, how will it add on my academic research profile? When I will apply for MS or PHD admission, will it count as publication?
A review paper is likely also known as a "survey paper", where you read (i.e. survey) related works in the field and then comment on them. Usually, a review paper should be able to contribute a small amount of knowledge in its own right to the field by providing a taxonomy of work.
Another type of paper that reviews extensively related work but isn't actually a review paper is a "systematic review paper" in which you usually ask a meta-question about the field.
If it appears in a refereed, peer-reviewed journal, then yes, it is a publication. In fact, if done well, these works can often have pretty high impact and can be cited very frequently. However, as already noted, since they don't usually involve substantial original research they need to be augmented with traditional research papers. If a graduate student has only survey papers or systematic review papers, I'd wonder as a search committee reviewer if this student did nothing but read related work rather than working on research.
With respect to MS or PhD applications, I'd think that the fact that you have a publication at all is already a bonus point for you. Most students who apply to these programs don't have publications.
One important distinction should be made between papers in the humanities and the sciences. In the sciences, it would be much more important to have "original research" papers where new ground is broken. In the humanities, by contrast, the act of studying the existing literature and critically evaluating it may, in and of itself, be considered an act of research. (Similarly, in medicine, "meta-studies" in which the reports of various experiments are synthesized to produce overall results and recommendations may also be considered very important, although they augment direct clinical research, rather than substitute for it.)
I have limited experience regarding since I am still a graduate student but from what I understand, a review paper is also a research paper. However, unlike a piece of research, where you study the existing literature, develop research questions and hypotheses, collect data, run experiments/analysis and make inferences which accept or reject your hypotheses, a review article is a summarization and collation of existing articles in a given, specific research topic.
There has been some semi-formal writings on this already namely, this and this. The consensus, so far, seems to be that review articles make fine additions to your publication record but not as fine as articles where you actually did your own research.
I would describe a review paper as different from a research paper. A research paper is one's original work that may be researched scientifically or otherwise, but a review paper is where someone goes through work already done/researched and gives suggestions as per that field of research. The suggestions would be if the objective, goal, problem were met by the researcher. Whether the research is of value now or in future, solutions to the problem, what is interesting, etc.