Why Women are almost dominant on HR functions specially recruitment?Is it because they are more emotional?

I agree completely with Amal.
It is not a matter of gender, it is a matter or abilities and expertise in the field.

It may appear that Women dominate HR Positions, however that is not true.
On the contrary, Men are quite inclined towards being in the Compensation & Benefits, Recruitment, etc functions today.
I believe that irrespective of the persons gender, it takes a very mature, practical, ethical and knowledgable person to be in such a function.
This is considering all the challenges and work involved in the HR function.