how to set rtk distance to total station distance(horizontal measurement only)?

You’re probably going to have to provide more details. @wizprod @chascoadmin and others can probably help.

what is the use of scale factor in total station?

if the UTM have scale factor of 0.9996

should i set my scale factor of my total station to 0.9996 so that my gathered data in my rtk will be equal to total station.

Here’s a good article on scale factors