How to convert response as a function to JSON

Question

The url I'm trying to fetch the data from:

"https://blob.niftyindices.com/jsonfiles/SectorialIndex/SectorialIndexDataNIFTY%20AUTO.js"

The response is a .js file. When I opened the file, this is the data I got:

modelDataAvailable({
    "groups": [{
        "label": "ASHOKLEY 2.8%",
        "weight": 2.8,
        "id": "1"
    }, {
        "label": "BHARATFORG 3.5%",
        "weight": 3.5,
        "id": "2"
    }, {
        "label": "BAJAJ-AUTO 9.61%",
        "weight": 9.61,
        "id": "3"
    }, {
        "label": "BALKRISIND 2.16%",
        "weight": 2.16,
        "id": "4"
    }, {
        "label": "BOSCHLTD 2.23%",
        "weight": 2.23,
        "id": "5"
    }, {
        "label": "EICHERMOT 5.82%",
        "weight": 5.82,
        "id": "6"
    }, {
        "label": "HEROMOTOCO 6.65%",
        "weight": 6.65,
        "id": "7"
    }, {
        "label": "M&M 16.38%",
        "weight": 16.38,
        "id": "8"
    }, {
        "label": "MARUTI 14.9%",
        "weight": 14.9,
        "id": "9"
    }, {
        "label": "MOTHERSON 2.98%",
        "weight": 2.98,
        "id": "10"
    }, {
        "label": "MRF 3.22%",
        "weight": 3.22,
        "id": "11"
    }, {
        "label": "SONACOMS 2.81%",
        "weight": 2.81,
        "id": "12"
    }, {
        "label": "TATAMOTORS 17.25%",
        "weight": 17.25,
        "id": "13"
    }, {
        "label": "TIINDIA 4.51%",
        "weight": 4.51,
        "id": "14"
    }, {
        "label": "TVSMOTOR 5.16%",
        "weight": 5.16,
        "id": "15"
    }, ]
}, {
    label: "NIFTY AUTO ",
    file: "SectorialIndexDataNIFTY AUTO.jsonp "
});

Now, my question is that the data is coming in the form of a function and not an object. So, how should I actually get the data in the object form so I can display that in the browser?