JSFiddle - React, Tailwind, and code Playground

JavaScript

var SchoolData =  {
        "SchoolRecord": {
            "classX": {
                "name": "Student Name 1",
                "subject": {
                    "mathsDept": {
                        "subject": "Maths",
                        "marks": 87
                    },
                    "scienceDept": {
                        "subject": "Physics",
                        "marks": 55                
                    },
                    "socialDept": {
                        "subject": "Social",
                        "marks": 95
                    }
                }
            },
            "classIX": {
                "name": "Student Name 2",
                 "subject": {
                    "mathsDept": {
                        "subject": "Maths",
                        "marks": 99
                    },
                    "scienceDept": {
                        "subject": "Physics",
                        "marks": 95
                    
                    },
                    "socialDept": {
                        "subject": "Social",
                        "marks": 91
                    }
                }
            }
        }
    }
    
    console.log(SchoolData.SchoolRecord);

console.log(SchoolData.SchoolRecord[0]);