Hi Akshay,
Asking for a full parkour system may be too broad as we dont know exactly what you mean. Its best to ask more specific questions so we can look at your Blueprint / code and help you.
I have a free template available that has some parkour elements (climbing, sliding, swinging, rope climbing, ladders, etc). Feel free to download the project and look at the code.
Download here - https://forums.unrealengine.com/showthread.php?125187-FREE-ThirdPerson-Action-Platformer
Hope this helps!