For the question to be more general, what are the criteria (including the acceptable No. of citations) that should be followed for writing a good review article?
Dear Mohammed, Do you mean how many studies should be included in any review paper? If so, I think as many studies as your area covered by studies. You should make a comprehensive review to analyze theme and summarize their results.
By definition, a review article should be as comprehensive as possible of the major seminal publications in a given area, and maybe also non-seminal ones for critical purposes. I can't give a figure because it all depends on the area's complexity and richness and the reviewer's limited or thorough knowledge of the specialization. However, the more, the better the area is covered.
I agree with the comments made by our friends. Just I need to add new idea may look for systematic literature review on your topic research instead of classic review paper. The SLR papers will give you statistical analysis and number of papers on your research based on some criteria in several digital libraries database.