How to get the row size of an 2 dim array in C

Hi there I was trying to make a varation of bucket sort. My Programm is easy because I'm a beginner in C but i don't know how print the 2 dim array when one row was realloc after putting in the numbers. I have tried int lenght= sizeof(buckets[0])/sizeof(buckets[0][0]) but then lenght=1. My alternativ solution in the main and it is not very dynamic therefore can anybody tell me how to get the size of the row in a 2 dim array?? If I would add a number in the first bucket the bucket will be too small so i realloc the bucket but how can i print it now? Sorry for the bad english :)

#include <stdlib.h>
#include <stdio.h>
#define MAXZAHL 50

int compare(const void * a, const void * b){// compare for the qsort
   return(*(int*)a - *(int*)b);
}

int** init_bucket(int l,int teile,int teilgr){// to init the buckets
    int **bucket;
    bucket=(int**)malloc(teile*sizeof(int));
    for (int i=0;i<teile;i++){
        bucket[i]=(int *)malloc(teilgr*sizeof(int));
    }
    for (int i=0;i<teile;i++){
        for (int j=0;j<teilgr;j++){
            bucket[i][j]=0;
            printf("%3i",bucket[i][j]);
        }
        printf("\n");
    }
    return bucket;
}
void bucket_int(int**bucket,int bucketsize,int nextVal,int n){// to write the   array in the buckets
     int start=bucketsize;
     for (int i=0;i<n;i++){
         if(nextVal< start && bucket[0][i]==0){
             bucket[0][i]=nextVal;
             break;
         }
         if(nextVal< start && bucket[0][i]!=0&& i==n-1){
             bucket[0][n]=(int)realloc(bucket,sizeof(int));
             ++i;
             bucket[0][i]=nextVal;
             break;
         }
         if((nextVal<(start*2)&& nextVal>=(start))&&(bucket[1][i]==0)){
              bucket[1][i]=nextVal;
              break;
         }
         if((nextVal<(start*3)&&nextVal>=(start*2))&&(bucket[2][i]==0)){
              bucket[2][i]=nextVal;
              break;
         }
         if((nextVal<(start*4)&&nextVal>=(start*3))&&(bucket[3][i]==0)){
              bucket[3][i]=nextVal;
              break;
         }
         if((nextVal<(start*5)&&nextVal>=(start*4))&&(bucket[4][i]==0)){
              bucket[4][i]=nextVal;
              break;
         }
    }
 }

int main(){
    int arr[]={3,26,2,10,33,45,20,15,11,9,34,40,19,16,4,5,26,49,1,0,6,8,7,3};
    int len=sizeof(arr)/sizeof(int);//
    int teile=5;
    int teilgr=MAXZAHL/5;
    int **buckets;
    buckets=init_bucket(len,teile,teilgr);
    for (int i=0;i<len;i++){//write the numbers in the buckets
        bucket_int(buckets,teilgr,arr[i],len);
    }
    printf("\n");
    //print Buckets
    for (int i=0;i<teile;i++){
        for (int j=0;j<teilgr;j++){// is there a way to say j<sizeof(buckets)??
            printf("%3i",buckets[i][j]);
        }
        printf("\n");
    }
    //sorting the buckets with qsort
    for (int i=0;i<teile;i++){
        for (int j=0;j<teilgr;j++){
            qsort(buckets[i],teilgr,sizeof(int**),compare);
        }
    }
    printf("\n");
    //print Buckets
    for (int i=0;i<teile;i++){
        for (int j=0;j<teilgr;j++){
            printf("%3i",buckets[i][j]);
        }
        printf("\n");
    }
    printf("\n");
    int f=0;
    //Putting the buckets back to the array
    for (int i=0;i<teile;i++){
        for (int j=0;j<teilgr;j++){
            if (buckets[i][j]!=0){
                arr[f]=buckets[i][j];
                f++;
            }
        }
    }
    printf("The sorted Array:\n");
    for (int i=0;i<len-1;i++){
        printf("%i ",arr[i]);
    }
    printf("\n");
    return EXIT_SUCCESS;
}