Hello,

First of all, enter the editing mode of the page where Slider Revolution displayed. Check which one is used as shown here: http://prntscr.com/isshej

Then find this slider in Slider Revolution plugin as shown: http://prntscr.com/issi0h

Finally edit the height in the slider settings as shown here: https://gyazo.com/00459a729601bec176cd0e6767a55bc6

Best Regards