JSFiddle - React, Tailwind, and code Playground

JavaScript

let word = 'olololo';

function reverseString(str) {
    var splitString = str.split("");
    var reverseArray = splitString.reverse();
    var joinArray = reverseArray.join(""); 
    return joinArray; 
}
 
let reverseWord = reverseString(word);
let result = findIndex(word);

function findIndex(string) {
  if (!isPalindrom(string)) {
    for (let i = 0; i < word.length; i++) {
      let newWord = removeLetter(word, i, 1);
      if (isPalindrom(newWord)) {
       return i;
      }  
      return "C этого слова не сделаешь палиндром";
    }
  } else {
  	return "Это палиндром";
  }
}

function removeLetter(str, startIndex, count) {
    return str.substr(0, startIndex) + str.substr(startIndex + count);
}
function isPalindrom(string) {
	let reversedString = reverseString(string);
	return reversedString === string;
}

console.log(result);