extract array from web fetched json file python

i want to fetch live quotes from this page in python 3 link

the quotes here is stored in json file in array "JsonData" i want to get the value stored in LTP inside the json file

from urllib.request import urlopen
import json


url = ("https://ewmw.edelweiss.in/api/Market/Process/GetFutureValue/BANKNIFTY/05%20Apr%202018")
response = urlopen(url)
data = response.read().decode("utf-8")
y = json.loads(data['JsonData'])
print(y)