Is it true that the Quran mentions "man" more than 800 times, whereas "women" are mentioned approximately 50 times? If so, why is there such a difference?
This claim is untrue and based on misunderstand Quranic verses.
'You may ask them for details , then you will see that they have misunderstood many Quranic verses.
Quran generally uses the word (man) for human beings whether man or woman. This is mentioned in most matters which concern man and woman, but in special matters of women, the word woman is mentioned.
Wassalam.