@anoohyabollampa1: FYI, the following Java 8 Solution has passed all test cases:

Java 8 Solution in O(N) with Disjoint Set

static java.util.function.IntUnaryOperator find;
static int[] componentsInGraph(int[][] gb) {
    int N = gb.length;
    int n = 2*N + 1;
    int[] parent = java.util.stream.IntStream.range(0, n).toArray();
    int[] size = java.util.stream.IntStream.range(0, n).map(i -> 1).toArray();

    // Find by Path Compression
    find = x -> {
        if(parent[x]!=x) parent[x]=find.applyAsInt(parent[x]);
        return parent[x];
    };

    // Union by Size
    for(int[] edge: gb) { 
        int root1 = find.applyAsInt(edge[0]);
        int root2 = find.applyAsInt(edge[1]);
        if(root1 == root2) continue;

        if(size[root1] > size[root2]) {                
            int r = root1;
            root1 = root2;
            root2 = r;
        }
        parent[root1] = root2;
        size[root2] += size[root1];
        size[root1] = 0;
    }

    IntSummaryStatistics s = Arrays.stream(size)
                                            .filter(i -> i>1)
                                            .summaryStatistics();
    return new int[]{s.getMin(), s.getMax()};
}