#include <iostream>
#include <bits/stdc++.h>
using namespace std;

bool palin(string s)
{

    string s1 = s;
    reverse(s1.begin(), s1.end());

    if (s == s1) {

        return true;
    }

    else {

        return false;
    }
}
int main() {
    int t;
    cin>>t;
    while(t--) {
        string s;
        int n,k;
        int count=0;
        cin>>n>>k;
        cin>>s;

        if(palin(s) && k==0) {
            cout<<"Yes"<<endl;

        }


        else {


        for(int i=0;i<(n/2);i++) {
            if(s[i]==s[n-i-1]) {
                continue;
            }
            else {
                s[i]=s[n-i-1];
                count++;
            }
        }


      if(count==k) {
          cout<<"Yes"<<endl;
      }
      else {
          cout<<"No"<<endl;
      }
        }
    }
    return 0;
}