trying to search element in 2d array

i am a beginner in c language and am trying to make a code which searchs an element in 2d array and its not working .if you see the problem please help out.

#include <stdio.h>
void main()
{
int arr[2][3]={{1,2,3},{4,5,6}};
printf("enter your number\n");
int n,row,column,i,j,flag=0;
scanf("%d",&n);

row = sizeof(arr)/sizeof(arr[0]);
column = sizeof(arr[0])/row;

for(i=0;i<row;i++)
{
    for(j=0;j<column;j++)
    {
        if(n==arr[i][j])
        {
            printf("the number is at index\n %d %d",i,j);
            flag=1;
            break;
        }
   
        if(flag==0)
        printf("this is not in the program\n");
        break;
    }
}

}

If you are not searching for the first element (value at arr[0][0]), the first if in the first iteration will not evaluate to true and flag won't be set to 1.
Therefore the second ifs body will be executed and the output is always gonna be "this is not in the program\n". In addition to that, I guess you want your break after that to be in the ifs scope.

So in fact you need to move that second if and the code belonging to it to the end of your code to get your desired results.

I am not sure if you want only the indices of the first found element to be printed or not. But I guess you want only one because of your break in the first ifs body?

If so you need to exit the outer for loop aswell. Your code then could look something like this:

#include <stdio.h>

void main()
{
    int arr[2][3] = { {1,2,3},{4,5,6} };
    int n, row, column, i, j, flag = 0;

    printf("enter your number\n");
    scanf("%d", &n);

    row = sizeof(arr) / sizeof(arr[0]);
    column = sizeof(arr[0]) / row;

    for (i = 0; i < row; i++)
    {
        for (j = 0; j < column; j++)
        {
            if (n == arr[i][j])
            {
                printf("the number is at index\n %d %d", i, j);
                flag = 1;
                break;
            }
        }

        if (flag != 0)
            break;
    }

    if (flag == 0)
        printf("this is not in the program\n");
}

And by the way what is the point of calculating row and column if both of these values are already hardcoded? I would suggest you could change them to be const ints and use them to create your array. You could have your variable definitions then like the following:

const int row = 2;
const int column = 3;
int arr[row][column] = { {1,2,3},{4,5,6} };
int n, i, j, flag = 0;