Hey Guys,
So as mentioned earlier, am a student doing vfx compositing and editing in school
I am practising iBK Gizmo and IBK Color in Nuke ( green screen footage ). I have attached a jpeg image for your reference. please let me know if the output - end result is fine. Or if not, then what should I do?
Thank You
Siraj Ganju 
Well, it’s very hard to tell. You should have a background in there because your keying will depend a lot on matching and merging to the background.
Tony Lyons has an excellent rundown on keying here: https://compositingmentor.com/category/advanced-keying-breakdown/
Do yourself a favor and go through all of it. It’ll make a world of difference!